Progressive problems in general chemistry

MEDICAL SCHOOL

COLLEGE OF PHARMACY

of Pharmacy

PROGEESSIVE PROBLEMS

GENERAL CHEMISTRY

BY
CHARLES BASKERVILLE, PH.D.

PROFESSOR OF CHEMISTRY
AND

W. L. ESTABROOKE, Pn.D.

INSTRUCTOR IN CHEMISTRY

COLLEGE OF THE CITY OF NEW YORK

College of Pharmacy

REVISED

D. C. HEATH & CO., PUBLISHERS
BOSTON NEW YORK CHICAGO

COPYRIGHT, 1910,
BY D. C. HEATH & Co.

2B O

PREFACE

THE application of the principles of a science is the
surest test of their understanding. The more thor-
oughly students are drilled with Problems, the surer
is the teacher that his work has been worth while.
To save time, and such is recognized as a distinct factor
in modern pedagogy, problems from many sources have
been brought together in this book. They have been
taken from college examinations (American, European,
and Australian), regents' examinations, College En-
trance Examination Board papers, text books of all kinds,
and such books dealing especially with chemical prob-
lems, arithmetic, or calculations as those of Thorpe, Tate,
Foye, Waddell, Taylor, Miller, Hale, Dennis, Carpenter,
Lupton, Talbot, etc. Many original problems have also
been incorporated. If the student has successfully
solved two hundred selected problems from this list,
it may be safely said that he has acquired a fairly sound
comprehension of the basic principles of chemistry.

No attempt is made to incorporate these principles,
for they are gone into in the presentation of the subject,
whatever text may be used or whatever method be pur-
sued. A type series, however, is given in Chapter XIV.
The number of problems is sufficiently great to admit
of the use of the book a number of years before solutions
of the problems may be handed down from one class
to another.

42*17

iv PREFACE

It will be observed that the student must seek much
necessary information from his text or such handy
reference books as Biedermann's Ohemiker Kalendar
or Van Nostrand's Chemical Annual by Olsen. Our
experience has shown good results accruing by hav-
ing such reference books conveniently placed in each
laboratory.

If the previous training of the student has been
sound, consideration of Chapter I may be omitted ; but
it may be well to prove this by testing. It is a remark-
able fact that college students, although they may
know the metric system thoroughly, cannot think in
its terms and are " up in the air" as soon as a question
is propounded in meters, cubic centimeters, etc.

No attempt has been made to render the nomenclature
uniform. The student thus has an opportunity to learn
the various terms in good usage among English-speak-
ing peoples, and he furthermore becomes more or less
familiar with the everyday parlance among so-called
practical men.

Our thanks are due Mrs. W. L. Estabrooke and
Mr. E. A. Stevens, who assisted in collating. Mr. W. A.
Hamor kindly followed the proofsheets.

REVISED EDITION

Helpful suggestions on the part of many teachers
have prompted us to incorporate much useful data in
an appendix. All detected errors have been corrected
and a booklet containing the answers to the problems
has been prepared. This may be obtained by teachers
on request to the publishers.

CHARLES BASKERVILLE.

JUNE, 1911. W. L. ESTABROOKE.

CONTENTS

CHAPTER PAGE

I. MEASUREMENT 1

Metric System

Linear Measure . . . . . • . 1

Surface Measure ...... 3

Volume ........ 4

Weight 6

Thermometry 8

Specific Gravity of Solids and Liquids . . .11

II. MOLECULAR WEIGHTS FROM ATOMIC WEIGHTS . 16

III. PERCENTAGE COMPOSITION 20

IV. CHANGES IN VOLUME 26

i. Due to change in pressure .... 26

ii. Due to change in temperature .... 29

iii. Due to change in both pressure and temperature 34
V. VOLUMES OF GASES FROM WEIGHTS — SPECIFIC

GRAVITY AND VAPOR DENSITY .... 48

VI. WEIGHTS FROM EQUATIONS 56

VII. VOLUMES FROM EQUATIONS . . . . .80
VIII. PROBLEMS IN COMBINING VOLUMES OF GASES

(Gay-Lussac's Law) 107

IX. CALCULATION OF FORMULAS ..... 118
X. ATOMIC AND MOLECULAR WEIGHT CALCULATIONS 129
XI. ELECTRO-CHEMICAL PROBLEMS ..... 140
XII. ANALYTICAL CALCULATIONS — STRENGTH OF SOLU-
TIONS 143

XIII. REVIEW — SYSTEMATIC AND MISCELLANEOUS . . 164

XIV. PROBLEMS BASED ON EQUATIONS .... 225

vi CONTENTS

APPBNDIX PAGE

I. INTERNATIONAL ATOMIC WEIGHTS .... 245

II. PERIODIC ARRANGEMENT OF THE ELEMENTS . . 246

III. THE METRIC SYSTEM — CONVERSION TABLES AND

MENSURATION RULES 247

IV. SPECIFIC GRAVITIES OF GASES .... 251
V. PHYSICAL CONSTANTS OF THE ELEMENTS . . 252

VI. VOLUME AND WEIGHT OF WATER FROM 0° TO

31° C 258

VII. VAPOR PRESSURE OF WATER FROM 0° TO

+ 100°C 259

VIII. ELECTRO-CHEMICAL EQUIVALENTS . . . . 260

IX. UNITS OF ELECTRICITY, HEAT, AND POWER . . 261

X. HEATS OF COMBINATION 262

XI. SPECIFIC RESISTANCE OF VARIOUS SUBSTANCES . 263

XII. DENSITIES OF VARIOUS SUBSTANCES . . . 264

XIII. TABLE OF SOLUBILITIES 266

XIV. PREPARATION OF SOLUTIONS 271

XV. STANDARD STOCK SOLUTIONS 275

XVI. COMPARISON OF CALCULATED AND OBSERVED DECOM-
POSITION ; VOLTAGES OF AQUEOUS SOLUTIONS . 278

PROGRESSIVE PROBLEMS IN
CHEMISTRY

CHAPTER I

Introduction

MEASUREMENT

Metric System — Linear Measure

1. Express 263.7018 m. as <» dm. ; (b) cm. ;
(<?) mm. ; (d) Dm. ; 0) Hm. ; (/) Km.

2. Express as m. (a) 5 Dm. ; (6) 4 Hm. ; (<?) 9 Dm. ;
00 8 Km.; (e) 32 Hm.; (/) 360 cm.; (#) 630 mm.

3. How many mm. in (a) 13 Km. ; (5) 92 Hm. ;
(<0 BOO Dm.; (d) 26.91 m. ; (e) 86.312 dm.;
(/) 8 cm.?

4. In a mile how many Km. ? How many m. ?
How many cm. ?

5. Express 10 yd. in m. ; in Km. ; in Hm. ; in cm. ;
in mm.

6. In 31.76 ft. how many m.? How many Km.?
How many cm. ? How many dm. ?

7. Convert 83 in. into (a) mm.; (&) cm.; (<?) Km.;
(<T) Hm, ; (» dm.

8. Find the value of the following expressions in m. :
O) 0.435 m. + 852 cm.-f 4263 mm. + 0.159 Km. ;
(b) 0.927 Km. - 6495 cm., 4.37 cm. - 42.87 mm. ;

l

2 PROGRESSIVE PROBLEMS IN CHEMISTRY

(<?) 8 x 0.0457 Km., 3.04 x 60.93 cm., 5.43 x 67.2 mm.;
(<f) 38,019 mm. -i- 0.097, 0.14 Km. -*- 25.625.

9. A book is 2.1 cm. thick; if the average thick-
ness of the leaves is 0.05 mm., find the number of
pages in the book.

10. The cost of building a railroad is $ 25,000 per
Km.; what is the cost of the road, if its length is
72 Km. and 53 in.?

11. The wheels of a locomotive that make 45 Km.
an hour are 7.5 m. in circumference ; how many revo-
lutions will they make a minute?

12. A train goes 1248 m. in 1J min. ; how many Km.
will it go in 1 hr., 35 min., and 15 sec.?

13. The top of a monument is 143.9 m., and the base
67.19 m. above the level of the sea; the steps which
lead from the base to the top of the monument are
each 19 cm. high. How many steps are there?

14. Sound travels 1130 ft. per second; how many
meters does it pass through per second?

15. It is 92,000,000 miles to the sun ; how many Km.
is it?

16. Light travels 186,000 miles per second ; how many
Km. per second is that ?

17. The mean height of the barometer in the latitude
of Greenwich at the level of the- sea is 30 in.; to how
many mm. is this equivalent?

18. How many dm. are equivalent to 106,725 mm.?

19. How many miles are there in 15 Km.?

20. In an English inch are contained 25.3995 mm.;
how many Km. are there in a mile?

MEASUREMENT 3

21. A nautical fathom is 6.087 ft. ; what is its value
in m. ?

Surface Measure

22. Multiply 5 dm. by 3 mm., and give the answer in
cm.

23. Reduce and give the answers to the following in
cm.2: (a) 1.51 m. x 2.5 dm.; (6) 0.35 m. x 3 cm.;
(c) 10 dm.2 -r-4 cm.; (d) 1.3 m.2 -T- 3 cm.

24. Measure the length and breadth of a sheet of paper
and give the result in decimeters; then compute how
many cm.2 could be cut from it.

25. Calculate the number of cm.2 contained on the
surface of a filter paper having a radius of 5 cm.

26. A round filter paper is 10 cm. across; what is its
area?

27. How many cm.2 are there in 15.5m.2? How
many dm.2 are contained in 108,642 cm.2 ?

28. Required the number of mm.2, cm.2, dm.2, con-
tained in the top of a table measuring 1m. x 70 cm.

29. Reduce the following to cm.2: (a) 2.8 dm.2;
(5) 3.1dm.2; (c) 1.35m.2; (d) 0.75dm.2 ; 0) 0.032 m.2;
(/) 0.0064dm.2; (<?) 700m.2.

30. Reduce the following to dm.2: (a) 53 cm.2;
(£) 7.3cm.2; (c) 0.003 cm.2; (d) 25m.2; <» 0.33 cm.2;
(/) 28.03 m.2.

31. How many cm.2 in a square one side of which is
(a) 1.7 dm.; (6) 35 dm.; (V) 1 m. ; (d) 0.035 dm.;
0) 3.2 dm.?

32. How many cm.2 in the following rectangles:
(a) 2dm. x 6cm. ; (6) 0.07m. x 7 cm.; (c) 3.2dm.
X 0.2 dm. ; '(<f) 58 dm. x 25 cm. ?

4 PROGRESSIVE PROBLEMS IN CHEMISTRY

33. Express 1 mm.2 as (&) the decimal of a cm.2;
(6) of a m.2; (c) of a dm.2.

34. Compute the area of a filter paper 12 cm. in dia-
meter. 7T = 3.14.

35. Required the number of (a) cm.2, (5) dm.2, and
(c) m.2 in 1,098,765,421 mm.2.

36. How many m.2 in 9 Dm.2; 8 Hm.2; 13 Km.2?

37. How many ca. in 9 a. ; in a Ha. ?

38. What part of a Ha. is an a.; a ca. ?

39. What part of a m.2 is a dm.2; a mm.2?

40. Convert 1,854,276 m.2 into Ha.; into Km.2.

41. Write 1.7431 m.2 as cm.2; as mm.2.

42. How many Km.2 in 17,467.5 Ha.?

43. How many cm.2 in 0.0137 m.2?

44. Write 3.571 cm.2 as mm.2.

45. A man bought 3 Ha. of land at |2.00 per Ha.
and sold it for $ 2.50 per a. ; how much did he gain ?

Volume

46. A cellar 20 m. x 50 m. x 3 m. is to be excavated;
what will it cost at 12 cents per m.3?

47. How many cc. are there in a block 12 cm. long,
8 cm. wide, and 5 cm. high?

48. How many m.3 are there in a wall 25 m. long,
8.4 m. high, and 76 cm. wide?

49. A wood pile contains 1800m.3; it is 15m. long
and 12 m. wide. How high is it?

50. How many cm.2 are there in one face of a cube
containing 729 cc. ?

MEASUREMENT 5

51. A gallon is equal to 3.7851.; how many cc. are
contained in one pint ?

52. Reduce 16 1. to U. S. gallons.

53. A beaker 6 cm. in diameter and 8 cm. high will
hold how many 1. of water?

54. A pneumatic trough is 3.1 dm. long by 1.9 dm.
wide and 1.5 dm. high, (a) How many 1. of water
will it hold? (6) How many dl. of water? (Y) How-
many cl. ? (cT) How many ml. ?

55. A cistern 1.42 m. x 8.4 dm. x 53 cm. will hold
what weight and volume of water?

56. A box is 1.2 dm. x 7 cm. x 30 mm. What is
the capacity in cc. ; also in 1. ?

57. Compute the contents of these boxes in 1. and in
cc. : (a) 12 cm. x 5 cm. x 4 cm. ; (5) 2.1 dm. x 3.2 dm.
X 10 cm.; <V) 1.04 m. x 1.03 m. x 1.02 m.

58. How many cc. in a slab of marble 1.5 m. x 7 dm.
x 9 cm. ? How many 1. of water will such a slab dis-
place ?

59. Reduce the following to cc. : (a) 3.7 dm.3; (5)
5.02 dm. »; (<?) 1.001 dm. 3; (d) 0.003 dm. 3; (V) 200
mm. 3 .

60. Reduce and express the following as indicated :
(a) 2 dm.3 to mm.3; (5) 5.7 dm.3 to mm.3; (V) 33.33
cm.3 to m.3; (d) 1.07 dm.3 to m.3.

61. A stick of timber 4 m. long and 3 dm. wide has
a solid contents of 240 dm.3; what is its thickness?

62. What is the capacity in 1. of a rectangular tank
2 m. long, 9 dm. wide, and 8 dm. deep?

63. What is the volume of a spherical glass bulb
which has a radius of 3 cm.?

6 PROGRESSIVE PROBLEMS IN CHEMISTRY

64. How many 1. of air are contained in a room
measuring 4 m. x 3 m. x 2 m.?

65. In 1.5 pints there are how many cc.? How many
mm.3 ?

66. How many 1. of water are contained in a tank
3 m. x 1.6 m. x 1.4 m.?

67. How many HI. in a bin 4 m. x 2 m. x 1 m. ?

68. How high must a box be to hold 30 1. if it is 50
cm. long and 20 cm. wide ?

69. In a m.3, how many dm.3 ; cc.3? What part
of a m.3 is a dm.3; a cc.3?

70. How many m. 3 in a rectangular box 125 cm. x
112 cm. x 80 cm. ? How many 1. ?

71. How deep must a cistern be to hold 6000 1. if the
bottom is a square measuring 2.25 m. on a side?

72. How many m. 3 of earth must be removed to dig
a ditch 90 m. x 85 cm. x 50 cm. ?

73. A cistern is 2m. x 1.5 m. x 1 m. ; how many 1.
of water will it hold ?

74. A cylinder of a steam engine is 3 ft. in diameter
and 5 ft. long; how many dm. 3 of steam will it contain ?

Weight

75. How many g. in 1 Kg.; 8 Dg. ; and 6 Hg. ?
What part of 1 g. is 1 eg. ; 1 dg. ; 1 mg.?

76. In a ton how many Kg. ? How many g. ?

77. A HI. of water weighs how many Kg. ? What
part of a ton ?

78. Change 0.546 Kg. to g.; to mg.; to eg.

79. Change 0.391 of a ton to Kg.

MEASUREMENT 7

80. How many eg. are contained in 2. 567 Kg. ? How
many g. are contained in 1.725 Kg. ?

81. How many eg. are contained in 2.567 Kg.? How
many mg. are contained in 5 cc. of water at -f-4°C.?

82. How many mg. are there in 0.9 dg. ? How
many in 1 Kg. ?

83. A cylindrical tube 90 mm. in length holds 1 g. of
water at + 4° C. Calculate its internal diameter.

84. What is the weight of water in a tank 1.3m.
x 80 cm. x 250 mm.?

85. How many g. of water in a bottle containing
0.391 1.?

86. A sample of water contains 4 g. of solid matter
per 1. ; to how many g. per gallon does this correspond?

87. A tank measures 2.5 m. x 3 m. x 6 m. ; how
many 1. of water will it hold? How many Kg. ?

88. A ton equals 1016.05 Kg. ; how many g. in 1 Ib.
avoirdupois?

89. A piece of platinum foil measuring 10.5 cm. by
1.5 cm. weighs 0.723 g.; into how many pieces, each
weighing 1 dg., may it be divided ?

90. A fine wire 255 mm. in length weighs 0.172 g.;
what length of such wire would it take to make a eg.
« rider " ?

91. How much space will 3.750 g. of water occupy?

92. A piece of Swedish filter paper measuring 60
cm.2 leaves on burning 0.1062 g. of ash. Calculate
the amount of ash left on burning filters possessing the
following radii: (a) 3 cm.; (5) 4 cm.; (<?) 5 cm.;
00 6 cm. ; 0) 8 cm. ; (/) 10 cm.

8 PROGRESSIVE PROBLEMS IN CHEMISTRY

93. Required the number of mg. in 115 cc. of water
measured at + 4° C.

94. A silver coin weighs 30 g. ; what volume of
water will it balance ?

95. A piece of platinum foil is 5.2 cm. x 0.7 cm. and
weighs 0.8 g. ; into how many pieces, each weighing
1J dg., may it be cut?

96. What weight of water is required to fill a vat
98 cm. x 71 cm. x 38 cm.?

97. A mass of 21.7 g. is divided into 70 pills; what
is the weight of each pill?

98. At 2 cents a Kg., what will 2.25 tons of hay cost?

99. At $ 6 a ton for coal, what will it cost to heat
a building 30 days if it takes 400 Kg. of coal a day ?

100. Into how many pieces of 325 mg. each may a
mass of 23.4 g. be divided ?

101. A liter of mercury weighs 13 Kg. 598 g.;
find the weight in Kg. of 3.69 1.

102. If 16.94 1. of olive oil weigh 15 Kg. 500 g., find
the weight of 1 1.

Thermometry

103. What temperature on the C. scale is equivalent
to + 250°F.?

104. What temperature C. corresponds to — 250° F.?

105. Change 0° F. to 0° C.

106. Express + 40° C. on the Fahrenheit scale.

107. Convert the following temperatures to C.°:
+ 40° F., + 2100° F., - 70° F.,
- 40° F., - 28° F., + 2700° F.

MEASUREMENT 9

108. Express the following temperatures in F.° :

+ 125° C., + 60° C., + 312° C.,

+ 15° C., + 480° C., - 273° C.

109. A Fahrenheit thermometer, immersed in a cer-
tain hot fluid, rises through -f- 50° ; through how
many degrees would a Centigrade thermometer have
risen under the same circumstances ?

no. What is the difference in temperature between
+ 72° C. and + 72° F. ?

111. What temperature on the Centigrade scale is
equal to + 212 F. ?

112. Express the following temperatures in C.° :
+ 60°F., -15.5°F., +0.2°F.
+ 10° F., + 500° F.,

113. Express the following temperatures in F.° :

+ 4° C., + 60° C., + 212° C.,

+ 15.5°C., +0.1°C., +1°C.

114. Reduce the following Centigrade degrees to the
Absolute scale :

+ 37°C., +26°C., +273°C., +11°C., - 12° C.,
+ 55° C., + 18° C., + 40° C., - 40° C.

115. Reduce the following Fahrenheit degrees to the
Absolute scale :

+ 25° F., + 60° F., + 1° F., - 8° F., - 30° F.

116. Reduce the following Fahrenheit temperatures
to the Centigrade scale :

+ 68° F., + 36° F., + 30° F., + 32° F., 0° F., - 40° F.,
- 44° F.s - 36° F., + 10° F., - 10° F., - 1° F.

10 PROGRESSIVE PROBLEMS IN CHEMISTRY

117. Reduce the following Centigrade degrees to
Fahrenheit :

+ 72° C., + 36° C., 0° C., + 4° C., -4° C., - 40° C.,
+ 40° C., - 273° C., + 273° C., - 1° C., + 1° C.

118. What must be the temperature of a liquid so
that both the Fahrenheit and Centigrade thermometers
shall read the same when immersed in it ?

119. Reduce + 8° C., + 20°C., + 70° C., - 40° C.,
and +10° C. to the Fahrenheit scale.

120. Reduce + 8° F., +40° F., + 180° F., - 10° F.,
and + 36° F. to the Centigrade scale.

121. Change these to the Absolute scale :

+ 79° F., + 79° C., + 31° C., - 60° C., - 5° C.

122. Sulphuric acid boils at -f- 338° C. ; what is the
corresponding boiling point on Fahrenheit's scale ?

123. Cast iron melts at + 2822° F. and tin at
+ 455° F. ; what is the difference between their melt-
ing points expressed in Centigrade degrees ?

124. Bromine boils at +138.7°F. ; what is the cor-
responding temperature on the Centigrade scale ?

125. Absolute zero is 273° below zero on the Cen-
tigrade scale; what is this temperature on the Fahren-
heit scale?

126. Iron melts at + 1200° C. ; what is the melting
point on the Fahrenheit scale?

127. The average difference in temperature between
two places is + 60° F. ; how much would this be on the
Centigrade scale ?

128. A low artificial temperature obtained is — 140° C . ;
what is the corresponding temperature in F. degrees ?

MEASUREMENT 11

129. Chloroform boils at +61.2° C., turpentine boils
at 4- 156°C., and glycerine boils at+290°C.; what are
the Fahrenheit readings?

130. At a certain temperature C. scale the reading is
as much below 0°.C. as it is above on the F. scale.
Find the readings.

131. Ether boils at + 34.5° C., alcohol at + 78.4° C.,
and sulphuric acid at + 338°C. ; what are the corre-
sponding boiling points on Fahrenheit's scale ?

132. Mercury freezes at - 40° C. and boils at + 350° C.
Calculate the corresponding temperatures on the scales
of Reaumur and Fahrenheit.

133. Cast iron melts at +1075° C., zinc at +423° C.,
lead at + 334° C., tin at +235° C. Calculate these tem-
peratures in F. degrees.

134. The difference between readings on C. and F.
scale is 64. Find the reading.

Specific G-ravity of Solids and Liquids

135. A piece of metal weighs 24.076 g. in air and
21. 2436 g. in water; what is its sp. gr. ?

136. A piece of mineral weighs 47 g. in air and 36.555
g. in water; what is its sp. gr. ?

137. A piece of iron ore weighs 27 g. in air and 21.6 g.
in water ; what is its sp. gr. ?

138. A certain fine powder weighs in the air 7 g. ; when
this powder is placed in a flask, and this flask is then
filled with water to a mark on the flask, the weight of
the flask, powder, and water to the mark is 59 g. The
weight of the flask filled with water only to the mark
is 55 g. What is the sp. gr. of the insoluble powder?

12 PROGRESSIVE PROBLEMS IN CHEMISTRY

139. A certain fine sand weighs 12 g. in the air. A
flask filled with water to mark weighs 47. 6 g. The
same flask containing the sand and filled to the same
mark with water weighs 56. 5 g. What is the sp. gr. of
the sand?

140. An empty bottle weighing 3. 5305 g. weighs when
filled with pure water 7. 6722 g., when filled with sea-
water 7. 7849 g. What is the sp. gr. of sea water?

141. A sample of sugar weighs 7.5 g. in the air and
4.6g. in petroleum ether of sp. gr. 0.64; what is the
sp. gr. of the sugar ?

142. Find the sp. gr. of common salt from the follow-
ing data : weight of salt in air, 8.85 g. ; weight of flask
and turpentine to mark, 45.24 g. ; weight of flask, salt,
and turpentine to mark, 50.56 g.; sp. gr. of turpentine,
0.86 g.

143. Find the relative densities of the following sub-
stances:

Granite Marble Hematite

Weight in air 409.82 g. 53.2841 g. 13.6287 g.
4* water 259. 31 g. 33.4020 g. 10.9406 g.

144. A sp. gr. flask holds 2.545 mg. of alcohol,
42.740 of mercury, and 5.829 of sulphuric acid. Calcu-
late the relative density of the sulphuric acid and
mercury, the density of the alcohol being 0.80.

145. A solid weighs in a vacuum 100 g. ; in water
85 g.; and in another liquid 88 g. What is the relative
density of this liquid?

146. Determine the relative density of gold from
the following data :

Weight of gold in air 4.6764 g.

Loss of weight in water 0.2447 g.

MEASUREMENT 13

147. A glass rod weighing 13 g. in air weighs 8 g.
in water and 3.8 g. in sulphuric acid; what is the sp. gr.
of the sulphuric acid ?

148. A piece of iron sulphide weighed in air 4.8934 g. ;
in water it weighed 3.8860 g. Calculate its relative
density.

149. Find the weight of a block of sulphur 50 m.3 in
Yolume and of relative density 2.05.

150. What is the weight of 1 1. of bromine, sp. gr.
3.19; of burning oil, sp. gr. 0.83; of alcohol, sp. gr.
0.80; of mercury, sp. gr. 13.59?

151. What is the volume of 1 Kg. of iron, sp. gr.
7.85; of magnesium, sp. gr. 1.74; of platinum, sp. gr.
21.5; of ice, sp. gr. 0.92?

152. A bottle holds 336 g. of water; it also holds
577.9 g. of sulphuric acid. What is the sp. gr. of the
acid?

153. A bottle weighs 80 g. when empty. Filled
with water it weighs 230 g. Filled with bromine it
weighs 560 g. ; with hydrochloric acid, 260 g. What is
the sp. gr. of the bromine and of the acid ? What is
the capacity of the bottle?

154. A bar of gold measures 34 by 10.5 by 11 cm.,

and weighs 75.87 Kg.; what is the sp. gr. of the gold?

155. A block of wood measures 49.8 by 60.5 by 210.
cm.; its sp. gr. is 0.63. What is the weight of the
block?

156. What is the weight of a m.3 of bromine, sp. gr.
3.19; of water at +4° C.; of sulphuric acid, sp. gr. 1.84?

157. The sp. gr. of HNO3 is 1.52. (a) Find weight
of 20 cc. ; (5) 87 cc. ; (V) how many cc. in 100 g. ?

14 PROGRESSIVE PROBLEMS IN CHEMISTRY

158. What is the weight of 40 cc. of sulphuric acid
having a sp. gr. of 1.84?

159. What is the volume of 3.6 Kg. of alcohol having
asp.gr. of 0.80?

160. A piece of metal weighs 3.7395 g. in air, 1.578 g.
in water, and 2.2896 g. in another liquid; what is
the sp. gr. of the metal and of the liquid?

161. A piece of platinum foil 14.2 cm. long and 2.5
mm. broad weighs 12 g.; find the thickness. Density
of platinum = 21.5.

162. A body weighing 18.5 g. when under water
weighs 16.4 g. and when in naphtha 16.72 g. ; what is
the sp.gr. of the naphtha?

163. Find the mass of 1 m.3 iron. Sp. gr. Fe = 7.80.

164. A mercury barometer stands at 76.1 mm.; what
would be the reading on a glycerine barometer?
Sp. gr. glycerine is 1.26, mercury is 13.59.

165. Nitric acid being 1.52 times as heavy as water,
what is the weight of 1 1. of the acid ?

166. A piece of sodium weighed 14.1563 g. in dry
air and 2.1807 g. in kerosene of sp.gr. 0.83; what is
the sp. gr. of sodium ?

167. A piece of metal weighs 47 g. in water and
48.756 g. in petroleum ether of sp. gr. 0.66; what is
the sp. gr. of the metal ?

168. A piece of brass weighs 10 g. in air, 8.824 g. in
water, and 9 g. in turpentine. Calculate the sp. gr. of
the turpentine.

169. If sulphuric acid has a sp. gr. of 1.84, how many
cc. of it will weigh 80 g. ?

MEASUREMENT 15

170. A block of marble 5cm. x 4cm. x 3cm. has a
sp. gr. of 2.7; how many g. will it weigh?

171. A lump of sodium carbonate (sp. gr. = 1.45)
is 65mm. x .4dm. x 3cm.; what does it weigh?

172. The sp. gr. of sulphuric acid is 1.84. A carboy
holds 5 gal. of 231 in.3 each. How heavy would the
contents of this carboy be?

173. What is the densit}^ of a cube of oak 9 mm.
along each edge and which weighs 0.62g.?

174. A cylinder of mahogany 10.1cm. high and
9.4 cm. across weighs 405.7 g. Find its density.

175. A block of steel (sp. gr. = 7.6) is 10 cm. square
and 1.8315 cm. thick. Find the mass of it in g.

176. What is the mass of a m.3 of hematite (sp. gr.
= 5.25)?

177. Find the volume of 1000 g. of sea water (sp. gr.
= 1.03).

178. Find the mass of a m.3 of anthracite (sp. gr.
= 1.4).

179. How many tons does a block of granite (sp. gr.
= 2.7) 10 x 3 x 2m. weigh?

180. If a glass ball weighing 7.7158 g. 2 cm. in diam-
eter just floats in a liquid, find the sp. gr. of the
liquid.

181. What is the density of K2Cr2O7, if 6. 2138 g. of
it displace 2.0532 g. of benzene (sp. gr. = 0.88)?

CHAPTER II

Molecular Weights from Atomic Weights
MOLECULAR WEIGHTS

Calculate the molecular weights of the following:

1. HC2H302; AlBr3; A14C3 ; A12O3; A1I3 ;
A1(N03)3; A1P04; A12(SO4)3; K2A12(SO4)4,24 H2O.

2. NH4C1; (NH4)2C03; NH4HCO3; (NH4)2CrO4;
NH4CN; NH4F; (NH4)2MoO4 ; NH4NO3; NH4NO2.

3. NH4C1O4; NH4H2P04; (NH4)2S ; NH4CNS;
(NH4)2W4013,8H20.

4. SbBr3; SbH3; Sb2O3; SbOCl; Sb2S3;
H3AsO4; As2O3.

5. AuCl3; Au2O3; Au2S3; AuBr3; Au2O ;
Ba(C2H302)2, H20 ; BaCO3.

6. BaCrO4; BaF2 ; BaSO4; BiBrg; BiONO3;
Bi2S3; H3B03; B6C.

7. BrCl,10H20; CdSO4; CdO ; CdS ; Cd(NO3)2;
Cd(CN)2; CdWO4; CsCl; CsBr; Cs2S5.

8. CaCO3; CaAl2O4; Ca(HCO3)2; CaO;
Ca(ClO3)2; CaF2; Ca(OH)2; CaI2; CaSO^; CO2.

9. C2Br4; C2C14; CS2 ; CO.

10. CeC2; Ce(NO3)4; CeO2; CeCl3; C12O; C12O7;
Cr03; CrCl3; Cr2(SO4)3.

16

MOLECULAR WEIGHTS 17

11. CrO2Cl2; Co2P; CoCl2; Co(NH3)6Cl3;
Co(OH)3; CbBr5; CbH ; CbN; Cb(HC2O4)5;
CbOBr3; Cb2OS3.

12. CuBr2; Cu2O; CuSO4,5H2O; CuCO3; CNOH;
C2N2; ErCl3,6H20; Er2O3; Er2(SO4)3.

13. FeAsO4,2H2O; FeCla ; FeCl3; FeCO3; Fe3O4;

FeS.

14. Ga2(SO4)3; Ga2S3 ; GeBr4 ; GeOCl2; BeCO3;
BeF2.

15. Au2P3 ; NH2,NH2 ; HC1 ; HCN ; H2O2 ; NH2OH ;
InBr3; InCl3.

16. In(CN)3; HIO3; Id; IrI3 ; IrS2 ; Fe3C •,
LaC2; La2O3; La2(SO4)3; La2S3.

17. Pb(C2H302)2; Pb(B02)2,H20; PbBr2;
Pb(N03)2; PbO; Pb3O4.

18. PbO2; LiBr; LiOH ; LiNO3; Li2C2O4; Li2O ;
MgC03.

19. MgF2; MgSO4,7H2O; MnCl2 ; Mn(OH)2 ;
HgCl2; HgS04.

20. HgCl; HgS; MoC ; MoCl3 ; MoSa; NdCl3,
6 H20 ; NdC2.

21. NiAs; Ni(C2H3O2)2; NiCO3; HNO3; N2;
N20; NOC1.

22. OsCl2; OsO4; OsS2; O2 ; PdBr2 ; Pd(CN)2 ;
PdS04, 2 H20.

23. PF3; PBr2N; Pt2O3 ; PtBr2; K2A12O4, 3 H2O;
K2PtCl4; KOH; PrCl3.

24. Pr2S3; RaBr2; RaC]2 ; RhCl3 ; Rh(SH)3;
Rh(OH)3; RbBr; Rb2CO3 ; RbF ; RbOH.

18 PROGRESSIVE PROBLEMS IN CHEMISTRY

25. RuCl2 ; Ru(OH)3; Ru2O3; SmC2 ; Sm(NO3)3,
6 H20 ; Sc203.

26. Sc2(SO4)3; Se2Br2; SeCl2 ; SeOCl2 ; SiHBr3 ;
SiF4.

27. AgC2H302; AgBr03; AgCl; Ag2Se ; Ag2S ;
NaCl; Na2SO4.

28. NaNO3; NaHCO3; NaAuCl4, 2 H2O ; Na8VO4,
16H2O; Na2WO4, 2 H2O.

29. SnO2; Sn2Fe(CN)6; SnFa ; SrBr2; SrC2 ;
Sr(Br03)2,H20; H2SO4 ; SOBr2 ; TaBr5.

30. Ta205; H2C4H406; TeO2 ; Tb2O3.

31. T1F; T10H; T1(NO3)3; ThBr4 ; Th(C2O4)2 ;
Ti6(CN)4; Ti203.

32. WBr2;W2C; WC14; WO2; H2WO4; H2UO4;
U2C3.

33. U02C12; HV03; VF3, 3 H2O ; Yb(C2H3O2)3,
2H02; Yb203; Yb2(SO4)3; YtBr3 ; Yt(NO8)8,
4H20.

34. ZnF2; Zn2Fe(CN)6, 3 H2O ; ZnSO4,6H2O;
ZrBr4; Zr(OH)4; ZrOCla, 8 H2O ; Zr(SO4)2, 4 H2O.

35. What are the molecular weights of the minerals
having the following formulas: (Ag2Pb)Se; (AgCu)2S ;
CuaSe ; (PbHg2)Se ; (PbCuAg2)Se ; Hg(SSe) ;
(HgZn)S; NiSb.

36. Ni(SbAs); Fe16S16; CoS2,CoAs; PtAs2 ;
RuS2; FeS2,FeAs; NiS2,Ni(AsSb)2; Cu2S,Bi2S3 ;
MnS2.

37. 9Ag2S,Sb2S3; Ag(ClBrl); (FeMg)O,TiO2;
MnO,Ti02 ; MgO,AlaO8 ; (FeMg)O,Fe2O3 ; FeO,
Cr203.

MOLECULAR WEIGHTS 19

38. Mn203,H20; (CaBa)CO3; CaCO3, (MgFe)CO3;
KAlSi308; (K2Ba)Al2Si4012 ; (NaK)AlSi3O8.

39. CaAlSi2O8; BaAl2Si2O8; H2Cs4Al4(SiO3)9;
NaFe(SiO3)2; HNaCa2(SiO3)3 ; (MnZnFeCa)SiO3.

40. (K2Na2MgCaMn)4(SiO3)4 ; NaAl(SiO3)2,
(FeMg)Si03 ; K2Na6Al8Si9O34 ;

(NaK)10Ca4Al12Si12052SCl4.

41. Na4(NaS3, Al)Al2(Si04)3 ; Bi4(SiO4)3;
Ca3Al2(SiO4)3 ; (FeZnMn)2[(ZnFe)2S]Be3(SiO4)3;

Ca3Cr2(Si04)3.

42. HCaBSiO6; HBeAlSiO5; Be2Fe(YO)2(SiO4)2 ;
(CaFe)2(A10H)(AlCeFe)2(Si04)3 ; CaB2(SiO4)2.

43. [Mg(FOH)]2Mg3(Si04)2 ; (Na2Ca)Al2Si6O16,
6 H20 ; CaAl2Si3010, 5 H2O;

44. H2KAl3(SiO4)3 ; KLi[Al(OHF)2] Al(SiO3)3 ;
[HK(MgFe)]3Mg3Al(Si04)3; (PbCl)Pb4(VO4)3.

45. (MnOH)MnAs04; (MgF)MgPO4;
(PbZn)2(OH)V04 ; (PbZnCu)2(OH)VO4;

Zn3As2O8, 8H2O.

CHAPTER III

Percentage Composition

1. Find per cent of potassium in (#) KBr ; (5)
KNO3 ; O) K2S04 ; (d) K2S.

2. Calculate the percentage of oxygen by weight in
mercuric oxide, manganese dioxide, potassium chlorate,
and water.

3. In borax (Na2B4O7, 10 H2O) find the percentage
O) of B ; (6) of Na ; (c) of O ; (d) of H2O.

4. Calculate the percentage composition of CaCO3,
CaC2, CaCl2, CO2, MgCO3, NaaCO8, and CO.

5. What is the per cent of tin in tinstone (SnO2),
in SnCl4, and in SnCl2 ?

6. Calculate the percentage composition of the fol-
lowing compounds :

Potassium ferrocyanide. . . . K4Fe(CN)6, 3 H2O.

Iso-creatine C4H9N3O2.

Rosaniline C20H21N3O.

Strychnine C21H22N2O2.

7. The skeleton of a man weighs 24 Ib. and con-
tains 58 per cent of calcium phosphate [Ca3(PO4)2].
Find the quantity of phosphorus present.

8. How much phosphorus can be obtained from 169
tons of bones containing 53.7 per cent of calcium phos-
phate ?

20

PERCENTAGE COMPOSITION 21

9. Find the percentage composition of crystallized
hydrogen disodium phosphate (Na2HPO4, 12H2O).

10. Find the per cent by weight of the elements
called for in the following: (#) per cent of oxygen in
HgO ; (5) of hydrogen in HC1 ; (<?) of lead in PbS ;
(d) of lead in Pb(NO3)2; (e) of each element in
Ca3(P04)2.

11. Find the percentage composition of H3PO4 to
one decimal place.

12. Find the percentage composition of ammonium
nitrate.

13. A sample of copper salt weighing 0.9864 g. is
dissolved in water and the copper deposited electrolyt-
ically. The weight of the electrode before passing the
current was 9.8609 g. ; at the end of the operation
10.1121 g. Find the per cent of copper in the sample.

14. Which is the richer in iron, Fe2O3 (hematite) or
Fe8O4 (magnetite) ? Compute.

15. Find the percentage composition of alcohol,
C2H60.

16. What per cent of sulphur is contained in pure
pyrite ?

17. Compute the percentage composition of Fe3O4 to
one decimal place.

18. Calculate the percentage of silica in potash mica
(KHAlSi04).

19. What per cent of silicon is in quartz ?

20. What per cent of magnesium is contained in
crystallized potassium magnesium sulphate, K2SO4,
MgSO4, 6H2O?

22 PROGRESSIVE PROBLEMS IN CHEMISTRY

21. What weight of potassium can be obtained from
20 g. of alum [K2A12(SO4)4, 24 H2O] ?

22. Find the percentage composition of bleaching
powder if its formula is Ca(OCl2).

23. 100 g. of each variety of sodium carbonate —
(a) Na2CO3, 10 H2O ; (ft) Na2CO3, 8 H2O ; (c) Na2CO3,
5 H2O ; (<T) Na2CO3, H2O — contain how many g. of
water ?

24. What is the percentage of («) barium oxide in
wither! te; (6) strontium oxide in strontianite; (c) zinc
oxide in calamine ?

25. Calculate the percentage composition of the
following compounds: carbon dioxide ; ammonia ; ferric
oxide ; acetic acid ; calcium sulphate ; cream of tartar ;
ferrous sulphate; common alum.

26. Calculate the percentage composition of cane
sugar and of glucose.

27. Calculate the percentage of water of hydration
in crystalline cupric sulphate.

28. What are the percentage compositions of sub-
stances possessing the following formulas : Mn3O4,
NaCl, and SiF4 ?

29. Calculate the percentage composition of propy-
lene (C3H6) and propane (C3H8).

30. Find the per cent of carbon in (CL) CH4; (b) C2H2;
00 C2H4; 09 COS; («) C4H10; (/) C6H10O5.

31. Calculate the percentage composition of the
following compounds:

Water, Calcium carbonate,

Potassium chlorate, Silver chloride,

Mercuric oxide, Magnesium pyrophosphate,

PERCENTAGE COMPOSITION 23

Potassium nitrate, Potassium platinum chloride,

Sodium nitrate, Sodium thiosulphate,

Barium sulphate, Magnetic oxide of iron.

32. How much weight will 32.2 g. crystallized sodium
sulphate lose on heating?

33. How many Ib. of dry Na2CO3 is contained in a
Ib. of crystallized washing soda?

34. How many Ib. of plaster of Paris can be made
by calcining 10 Kg. of gypsum ?

35. What is the percentage of sodium in Glauber's
salt?

36. How many g. of C and of S are contained in
1292 g. of CS2?

37. It is required to find the weight of iron in 1000
Kg. of ferric oxide.

38. How many g. of copper in 3 Kg. of Scheele's
green (CuHAsO3)?

39. What weight of Ca, P, and O are contained in
100 g. bone ash ?

40. How much oxygen in 10 g. lime ; 6 g. litharge ; 4
g. nitric acid; 10 g. sand?

41. How many g. of sodium in J ton of NaNO3?

42. How many g. of mercury in 20 g. of (#) corrosive
sublimate; (£>) 26 g. calomel; (c) 13 g. mercuric sul-
phide ?

43. How much sodium in (a) 10 g. NaOH; (6) 6 g.
Na2S04; <» 14 g. NaCl; (d) 2 g. NaHSO4?

44. Find the percentage composition of (CL) galena;
(&) zinc blende.

45. Find the percentage composition of Cu(NO3)2;
Pb(N03)2.

24 PROGRESSIVE PROBLEMS IN CHEMISTRY

46. It was found by experiment that 10 g. of crys-
tallized sodium sulphate contained 4.70 g. of water;
how many molecules of water of hydration does the
crystallized salt contain?

47. What is the percentage of copper in crystallized
copper sulphate?

48. What is the percentage of nitrogen in "caliche"
that is 97.8 per cent pure?

49. A room 15 ft. long and 10 ft. wide and high is
covered with a paper containing 0.78 g. of Scheele's
green per ft.2. How much arsenic is there in the
room ?

50. How many g. of Pb is contained in each of the
following: (a) 10 g. litharge; (b~) 10 g. minium; (Y)
10 g. lead peroxide ?

51. Which is cheaper, Na2B4O7, 10 H2O at 7 cents a
pound, or the anhydrous salt at 5 cents a pound ?

52. How many Kg. of water will be set free when
1 ton of crystallized copper sulphate is converted into
the anhydrous condition on heating ?

53. How much copper in (#) 10 g. Cu2O ; (5)
13 g. azurite [2 CuCO3, Cu(OH)2] ; (<?) 2 g. CuS ?

54. What is the weight of Ca in 3 g. of calcium
sulphate ?

55. One g. of soft coal on analysis gave 0.0593 g. of
barium sulphate. What is the percentage of sulphur
in the sample of coal ?

56. How much arsenic is there in 3 g. of magnesium
arsenite ?

57. Five g. of galena gave on analysis 5 g. of lead
sulphate. What is the percentage of lead ?

PERCENTAGE COMPOSITION 25

58. How many pounds of red lead can be made from
500 Ib. of litharge ?

59. How much anhydrous salt in a Kg. of crystalline
(a) copper sulphate ; (6) washing soda ; (c) Epsom
salts ; (d) alum ; (e) Glauber's salt ?

60. Find the g. of lead in (a) 21 g. PbO2 ; (6) 13 g.
PbSO4; (V) 14 g. sugar of lead; (d) 91 g. cerussite
(PbC03).

61. How much (1) oxygen, (2) chlorine, can be
obtained from 100 g. bleaching powder ?

62. How many pounds of phosphorus in 265 pounds
of calcium phosphate ?

63. What weight of barium sulphate can be obtained
from 10 g. of crystallized magnesium sulphate ?

64. Calculate the percentage composition of Na2S2O3,
5 H2O ; find the number of g. of water in 17 g. of the
salt.

65. Find the percentage of hydrogen in (a) HC1;
(5) H2S ; 0) NH3; (d) CH4 ; (e) HF.

66. KC1O3 is 39 <jo oxygen ; calculate the g. of oxygen
in (a) 76 g. ; (6) 276 g. ; and (c) 700 g.

67. A sample of air consists of 12.37 g. N and 3.63
g. O. Find the percentage of each.

CHAPTER IV

Changes in Volume

Due to (/) changes in pressure alone ;

changes in temperature alone;

changes in both temperature and pressure.

I. Changes in volume due to difference in pressure.

1. The pressure on 134 cc. of air is increased from
480 mm. to 1200 mm. Find the new volume.

2. The pressure of 240 cc. of nitrogen is increased
from 720 mm. to 780 mm. Find the new volume.

3. The pressure of 25 1. HC1 is decreased from 863
mm. to 621 mm. Find the new volume.

4. The pressure of 15 1. of oxygen is increased from
700 mm. to 800 mm. Find the new volume.

5. The pressure on 10 cc. of gas is 7 m. ; if the
pressure is reduced to 847 mm., what is the new vol-
ume?

6. The pressure of 1000 cc. of a gas is decreased
from 774 mm. to 600 mm. Find the new volume.

7. The pressure of 512 cc. of hydrogen is increased
from 744 mm. to 790.5 mm. Find the new volume.

8. The barometric pressure of 5000 cc. of hydrogen
is increased from 740 mm. to 760 mm. Find the new
volume.

26

CHANGES IN VOLUME 27

9. Reduce the following volumes to the volume oc-
cupied at standard pressure : («) 221 cc. at 963 mm. ;
(ft) 30 cc. at 662 mm. ; (V) 100 1. at 1461 mm.

10. Under standard conditions 1 1. of oxygen weighs
1.4336 g. ; what is the pressure when 1 1. weighs 1.29 g.

11. Under a pressure of 745 mm. 1500 cc. of a gas
weigh 1.9762 g. ; what is the weight per 1. under
standard pressure?

12. A body of gas occupies 2000 cc. when the ba-
rometer stands at 750 mm. What volume, at the same
temperature, will it occupy at 760 mm.?

13. I have 4-| 1. oxygen under a pressure of 750 mm.
At 730 mm., what space will it fill?

14. At 850 mm., what should be the volume of a gas
which at 600 mm. fills 100 cc. ?

15. What volume will the same gas occupy at 200
mm. pressure?

16. One 1. of air at normal pressure and temperature
weighs 1.293 g. Under what pressure will the same
volume weigh 2 g. ?

17. CO has a volume of 18 1. at a pressure of 500
mm. Find volume at 650 mm.

18. If 27 1. of gas at 690 mm. now occupy 31 1.,
what is the new pressure?

19. A balloon containing 1200 cm.3 of coal gas under
a pressure of 770 mm. ascends until the barometer
stands at 530 mm. What volume would the gas in the
balloon now occupy, supposing none to have escaped ?

20. A certain volume of air preserved at a constant
temperature measures 150 cc. when the barometer
stands at 760 mm. On the following day its volume

28 PROGRESSIVE PROBLEMS IN CHEMISTRY

is found to have decreased 1.52 cc. Calculate the al-
teration in the height of the barometer which must
have ensued.

21. What will be the excess of pressure inside a
bottle of soda water when four volumes of carbon di-
oxide are dissolved in one volume of water?

22. A volume of hydrogen measuring 195 cc. when
the barometer stood at 740 mm. was afterward found
to measure 200 cc. What was the height of the ba-
rometer at that time ?

23. A flask having a capacity of 4.5 1. is filled with
a gas when the barometer stands at 755 mm. What
would be the volume of the same gas in cc. when the
barometer stands at 762 mm. ?

24. A volume of hydrogen in a bell jar over mercury
measured 524 cc. The mercury in the jar was 54 mm.
above the surface of the mercury in the trough, and the
barometer stood at 745 mm. What would have been
the volume if exposed to the standard pressure alone?

25. A volume of gas was found to be equal to 250
cc. when the height of the barometer was 742 mm.
What would have been the volume had the barometer
stood at 760 mm. ?

26. A volume of gas measured 467 cc. when the
barometer stood at 756 mm. What would it have
measured had the barometer stood at 760 mm. ?

27. A volume of air measured 137 cc. when the
barometer stood at 766 mm. What would it have
measured had the barometer stood at 757 mm. ?

28. If a certain mass of gas occupies 800 cc. at a
pressure of 76 cm., what would its volume be at 74 cm.
pressure ?

CHANGES IN VOLUME 29

29. Into what space must 60 ft.3 of air be com-
pressed that its expansive force may be made twelve
times as great ?

30. How strong would a compression tank have to
be if its capacity is 600 in.3 and 5 ft.3 of air at normal
pressure is forced into it ?

31. What will be the weight of a 1. of air under a
pressure of 300 in. of mercury ?

32. A rectangular diving bell 14 ft. high is sunk to
the bottom of a lake at a point where the water is 60
ft. deep. Find how high the water will rise in the bell.

II. Volume with temperature alone changing.

33. If 170 volumes of oxygen are measured at -f- 10° C.,
what will the volume be when the temperature falls to
0°C.?

34. If 10 cc. of a gas are measured at + 15° C., what
volume will the gas occupy at + 150° C. ?

35. If 100 cc. of hydrogen are measured at + 200° C.,
how many cc. will the gas occupy at — 200° C. ?

36. Calculate the temperature at which air possesses
a density equal to that of hydrogen at 0° C.

37. A mass of gas at 0°C. measures 2000 cc. Find
the volume at (a) - 7° C. ; (ft) + 10° C. ; (c) + 27° C. ;
(d) + 106°C.; <V)-230C.

38. An open vessel was heated until one-third of the
air it contained at 0° C. was driven out ; how much
was it heated ?

39. How much must a 1. of air at + 10° C. be heated
in order to increase its volume two-thirds ?

30 PROGRESSIVE PROBLEMS IN CHEMISTRY

40. At what temperature would nitrogen have the
same density that hydrogen has at 0° C. ?

41. What will be the volume of 250 cc. of hydrogen
measured at + 30° C. when cooled to - 10° C. ? "

42. What will be the volume at + 25° C. of 252 cc. of
oxygen measured at + 15° C. ?

43. If 170 volumes of oxygen are measured at
+ 10°C., what will the volume be if the temperature
falls to 0° C. ?

44. When 600 cc. of oxygen at + 21° C. are cooled to
— 8° C., what is the new volume ?

45. A certain weight of air measures a 1. at 0° C. ;
how much will the air expand on being heated to
+ 100° C. ?

46. What is the temperature when 15 1. of a gas at
+ 20° C. will occupy a volume of 18.6 1. ?

47. A flask holding 600 cc. of air at 0° C. is heated to
H- 25° C. ; what volume of expanded air escapes ? Tem-
perature of escaped air is + 25° C. Neglect expansion
of flask.

48. A volume of gas measuring 500 cc. at 0° C. was
expanded by heating to 600 cc. at constant atmospheric
pressure ; what temperature did the gas attain ?

49. A rubber balloon containing 400 cc. of oxygen
measured at — 20° C. is subjected to a temperature of
-h 120° C. What is the increase in volume of the
balloon ?

50. At what temperature will 1 1. of chlorine weigh
the same as 1 1. of hydrogen ; 1 1. of N2O ; 1 1. of NH3?

51. If 100 cc. of a gas at +10° C. is found to change
its volume to 110 cc., at what temperature is it then?

CHANGES IN VOLUME 31

52. The temperature of a gas being raised from
- 15° C. to +10° C., it now measures 200 cc. Find the
original volume.

53. What volume will 1000 cc. of air at+13°C.
occupy at +65° C. ?

54. If 300 cc. of gas are measured off at+28°C.,
what will the volume become at — 14° C. ?

55. A 1. of gas is heated from + 14° C. to + 42°C.
Find the new volume.

56. A 1. of air at + 39° C. is cooled to - 26° C. Find
the new volume.

57. What volume will 50 cc. of gas at + 10° C. occupy

at+24°C.?

58. If 100 cc. of air at +12° C. are heated until they
occupy 145 cc., what is the new temperature ?

59. A volume of air, measuring 230 cc., was standing
in a 1. flask over water, the temperature of which was
+ 26° C. The temperature was then raised to +60°C.
How much water then remained in the flask?

60. I have a 1. flask full of hydrogen at + 15°C. I
wish to expel half the gas. To what temperature must
it be heated ?

61. I have a 1. flask full of oxygen standing over
water at +90°C. I wish 100 cc. of water to enter the
flask. What must be the temperature?

62. 3 1. of chlorine and 5 1. of hydrogen were mixed
and exposed to sunlight at a temperature of -f 15° C.
It was found, after the HC1 had been formed, that the
temperature had risen to + 40° C. What volume did
the gases then occupy?

32 PROGRESSIVE PROBLEMS IN CHEMISTRY

63. Below +500° C. sulphur has six atoms to the
molecule ; above 4-500° C. it has only two atoms to the
molecule. We have 300 cc. of sulphur gas at +450° C.
What will be the volume at + 800° C. ?

64. If 1000 cc. of gas are heated from 0° C. to + 39° C.,
what is the new volume ?

65. If 1000 cc. of gas are heated *from+39°C. to
+ 52° C., what is the new volume?

66. What volume will 20 ft.3 of air at -7° C. have

at+7°C.?

67. If the vapor density of a gas is 32 at the temper-
ature of -f-15°C., at what temperature will it have a
vapor density of 28.16?

68. A quantity of gas was measured when its tem-
perature was + 12 °C. At what temperature would its
volume be doubled?

69. An open vessel was heated to + 819° C. What
portion of the air that the vessel contained at 0° C. re-
mained in it?

70. An open vessel was heated till l of the gas that
it contained at + 15° C. was driven out. What was the
temperature of the vessel?

71. A volume of air measured 475 cc. at + 27° C.
What would have been its volume at 0° C. ?

72. A quantity of hydrogen measured 550 cc. at
4- 15° C. What would have been its volume had its
temperature been —10° C. ?

73. A given weight of air measured 256 cc. at
+ 34° C. What would have been its volume had its
temperature been 0° C. ?

CHANGES IN VOLUME 33

74. A volume of nitrogen measured 3.5 1. at -f- 75° C.
What would have been its volume had its temperature
been + 15° C. ?

75. A volume of gas measured 50 cc. at -h 15° C. At
what temperature would its volume be 44 cc. ?

76. What volume will 400 1. of illuminating gas at
+ 60° C. occupy at + 22° C., if there is no change of"
pressure ?

77. If 100 cc. of hydrogen are measured at 4- 100° C.,
how many cc. will the gas occupy at —100° C. ?

78. What volume will 1000 cc. of hydrogen at 0° C.
occupy at (a) + 15° C. ; (6) + 20° C. ; (e?) + 300° C. ?

79. A gas has its temperature raised from +19° C. to
+ 50° C. ; at the latter temperature it measures 15 1.
What was the initial volume ?

80. A certain weight of air measures a 1. at 0° C.
How much will the air expand on being heated to
+ 100° C. ?

81. A volume of hydrogen measures 1500 cc. at 0° C.
How many cc. will it measure at (#) + 15.5° C. ; (5) at
+ 50° C. ; (<?) at +400° C. ; (d) at +600°C.? At
what temperature will it measure exactly 1000 cc. ?

82. If 10 cc. of a gas are measured at + 18° C., what
volume will the gas occupy at + 150° C. ?

83. Calculate the temperature at which air possesses
a density equal to that of methane at 0° C.

84. If the sp. gr. of air at -f 20° C. normal pressure
is 0.00118, what will be the weight of a 1. of air at
- 20° C. ?

85. A volume of air at 0° C. measures 1 1. ; what will
be its volume at + 18° C. ?

34 PROGRESSIVE PROBLEMS IN CHEMISTRY

86. A volume of air at + 91° C. measures 1000 cc.
Reduce the volume to standard temperature.

87. An open vessel is heated from 0° C. to + 546° C.
What portion of the air that it at first contained now
remains ?

88. Find the volume of the following at 0° C. : (a)
"170 cc. at + 13° C. ; (5) 400 cc. at + 14° C. ; (<?) 771
cc. at +1° C. ; (d) 288 cc. at - 7° C. ; <» 300 cc.
at + 200° C.

89. A 1. flask filled with air at — 10° C. is heated to
+ 70° C. What will be the volume of the air that
escapes if measured at 0° C. ?

III. Volume with pressure and temperature both changed.

90. Given 800 cc. of nitrogen at -- 1° C. and 721
mm., what will be the volume at + 1° C. and ^ an at-
mosphere pressure ?

91. A certain quantity of nitrogen measures 155 cc.
at + 10° C. and under a pressure of 530 mm. What
will the volume become at + 18.7° C. and under a pres-
sure of 590 mm. ?

92. A volume of hydrogen at a temperature of + 15°
C. measured 2.7 1. when the barometer stood at 752mm.
What would have been its volume had its temperature
been + 9° C. and the barometer stood at 762 mm.?

93. Given 18 cc. gas at + 16° C. and 772 mm., what
will be the volume at 0° C. and 760 mm. ?

94. Given 14 cc. gas at + 11° C. and 900 mm., what
will be the volume at + 3° C. and 790 mm. ?

95. Given 2.7 1. at + 18° C. and 749 mm., what will
be the volume at 0° C. and 760 mm. ?

CHANGES IN VOLUME 35

96. Given 500 cc. of a gas at +163° C. and 8.72
mm., find its volume at + 77° C. and 10 mm. •

97. A volume of air at standard temperature and
pressure is compressed to J its original volume, and the
temperature is then raised to + 25° C. What will now
be the pressure in atmospheres?

98. If 1500 cc. of nitrogen at +57° C. and 780 mm.
are cooled to + 27° C., the pressure being decreased to
740 mm., what is the new volume?

99. Given 500 cc. of hydrogen at + 25° C. and 760
mm. pressure, what will be the volume at -f 115° C. and
755mm.?

100. I fill a flask of 2 1. capacity with hydrogen when
the thermometer indicates + 25° C. and the barometer
762 mm. What is 'the volume at 0° C. and 760 mm.?

101. I measure a volume of nitrous oxide at 755 mm.
and -f 17° C., and find 360 cc. What volume should it
occupy at 960 mm. and + 37° C. ?

102. Compute the. volume of carbon dioxide at 300
mm. and + 50° C. which is 25 1. at + 20° C. and 700
mm.

103. A certain mass of gas measures 11,000 gal. at
+ 14° C. and 740 mm. pressure. To what volume will
it expand when the temperature reaches + 27° C. and
the pressure 620 mm. ?

104. If 100 1. of gas at + 30° C. and 731 mm. is
cooled to -f 25° C. while the pressure rises to 790 mm.,
and is then measured again, what is its new volume ?

105. Given 500 1. of ammonia gas at + 135° C. and
752 mm., what will be its volume at + 100° C. and 760
mm. ?

36 PROGRESSIVE PROBLEMS IN CHEMISTRY

106. Given 730 cc. of nitrogen at + 25°C. and 770
mm., what will be the volume of this mass of gas at
- 30° C. and 710 mm. ?

107. A quantity of illuminating gas measures 5 1.
and 25 cc. at + 17° C. and 760 mm. What will be its
volume at + 100° C. and 735 mm. ?

108. If 175 cc. of gas are measured at + 20° C. and
785 mm., what would be the volume of the same mass
of gas at 0° C. and 760 mm. ?

109. Given 125 cc. of gas at +1°C. and 750mm.,
what will be the volume at 0° C. and 650 mm. ?

110. Given 40 pt. of gas at + 10° C. and 740 mm.,
what is the volume at — 10° C. and 630 mm. ?

111. Given 1 ft.3 of gas at — 110° C. and 510 mm.,
what is the volume at + 25° C. and 820 mm. ?

112. Given 1 gal. of gas at -f- 21° C. and 722 mm.,
what is the volume at 0° C. and 760 mm. ?

113. Given 300 1. of gas at - 100° C. and 310 mm.,
what is the volume at 0° C. and 760 mm.?

114. Given 22.16 m.3 of gas at 0°C. and 760 mm.,
what is the volume at + 25° C. and 750 mm. ?

115. Given 0.18 1. of gas at 0° C. and 760 mm., what
is the volume at — 25° C. and 770 mm. ?

116. If a room measures 10 m. by 100 dm. by 1000
cm., what volume of air will escape from it if the tem-
perature changes from —11° C. to —15° C. ? What vol-
ume if the pressure changes from 760 mm. to 735 mm. ?
What volume if both temperature and pressure change
together ?

117. What mass of oxygen at + 10° C. and 750 mm.
would fill a globe of 16 1. capacity ?

CHANGES IN VOLUME 37

118. If the volume of a mass of ammonia is 500 cc.
at + 40°C. and under the pressure, of 60 mm., what
would it be under the pressure of 35 mm. at + 20° C. ?

119. If the volume of a mass of nitrogen is 50 cc. at
-f- 20° C. and under the pressure of 60 cm., what would
it be under the pressure of 900 mm. at + 100° C.?

120. If the volume of a mass of carbon dioxide is
2050 cc. at +200°C. and under the pressure of 5 cm.,
what would be the volume in 1. under the pressure of
400 mm. at + 50° C. ?

121. If the volume of a mass of steam is 50,000 cc.
at 200° C. and under the pressure of 1200 cm., what
would be the volume in 1. under the pressure of 20,000
mm. at + 250° C. ?

122. If 470 cc. of nitrous oxide at + 40° C. stand in
a tube over mercury, the level within the tube being 70
mm. above that without, and the barometric pressure
being 740 mm., what would be the volume of the gas at
+ 15°C., the barometric pressure being 765 mm. and
the level within the tube being 20 mm. below that
without ?

123. If 1 1. of carbon dioxide at -f 18° C. stand in a
tube over mercury, the level within the tube being 125
mm. below that without, and the barometric pressure
being 755 mm., what would be the volume of the gas at
H- 50° C., the barometric pressure being 74 cm. and the
level within the tube being 500 mm. above that with-
out?

124. If 300 cc. of air at +20°C. stand in a tube
over mercury, the level within the tube being 20 cm.
above that without, and the barometric pressure being
750 mm., what would be the volume of the gas at

38 PROGRESSIVE PROBLEMS IN CHEMISTRY

-j-100°C., the barometric pressure being 760 mm. and
the level within the tube being 70 cm. above that with-
out ?

125. If the pressure of 300 cc. of gas is 600 mm. at
+ 5°C., what pressure would be required to maintain
the volume at 350 cc. at + 100° C. ?

126. What volume will 30 g. of oxygen occupy at
4- 200° C. under the pressure of 80 cm. of mercury ?

127. At what temperature will J Kg. of sulphur
dioxide have a volume of 40 1. under 5 atmospheres
pressure ?

128. How many g. of nitrous oxide will occupy 900
cc. under the pressure of 2 atmospheres at 4- 50° C. ?

129. If 320 cc. of gas are measured at + 91° C. and
950 mm., what is the normal volume ?

130. If 542 cc. of air at +269°C. and 900 mm. are
cooled to + 51° C., the pressure being decreased to 666
mm., what is the new volume ?

131. If 546 cc. of gas at + 17°C. and 760 mm. are
cooled to 0°C., the pressure being decreased to 600
mm., what is the new volume ?

132. A quantity of oxygen which measures 230 1. at
+ 14° C. and 740 mm. will measure how much at 0° C.
and 760 mm. ?

133. If 1234 cc. of normal gas are cooled to — 52° C.,
the pressure being decreased to 617 mm., what is the
new volume ?

134. The volume of a gas contained in a tube measures
86 cc., the mercury standing at a height of 34 mm. in
the tube. Barometric pressure is 742 mm. ; temperature
is + 23° C. What is the normal volume of the gas?

CHANGES IN VOLUME 39

135. One 1. of oxygen at 0° C. and 760 mm. pres-
sure weighs 1.4296 g. What will it weigh at the
same temperature with the barometer standing at 780
mm. ?

136. What will be the weight of 300 cc. of oxygen at
+ 18° C. and with the barometer at 730 mm. ?

137. Under standard pressure at what temperature
will 1 1. of oxygen weigh 1 g. ?

138. What will be the volume of 200 g. of oxygen at
770 mm. pressure and + 27° C. ?

139. A volume of hydrogen measuring 500 cc. at
+ 25° C. and 730 mm. was reduced in volume to 400 cc.
at 0° C. What was the final pressure of the gas?

140. If 150 cc. of air are measured over water at
4- 18° C. and 746 mm. pressure, what will be the
volume at standard conditions?

141. Since 1 1. of oxygen at standard conditions
weighs 1.429 g., 440 cc. of this gas measured over
water at + 24° C. and 742 mm. pressure will contain
what weight of the dry gas ?

142. What increase in pressure is necessary to force
100 cc. of hydrogen at -f 46° C. and 740 mm. into a
vessel of 80 cc. capacity, when the temperature of this
vessel is constant at 0° C. ?

143. Find volume under standard conditions of a mass
of oxygen occupying 75 cc. at + 40° C. and 750 mm.
pressure.

144. Chlorine occupies 20 1. at 720 mm. and -f 20° C.
Find volume when conditions change to 790 mm. and
+ 30° C.

40 PROGRESSIVE PROBLEMS IN CHEMISTRY

145. A flask of air at standard conditions weighs 26
g. What capacity must it be, when filled with oxygen
at + 14° C. and 753 mm., to weigh 26.73 g. ?

146. The conditions in a vessel are +11° C. and
800 mm. What expansion would there be if the tem-
perature changed to -+-100°C. and the pressure to
766 mm. ?

147. A cylinder contains air at + 5° C. and 4 atmos-
pheres pressure. Show that if the air is heated to
+ 565° C. the cylinder must be able to stand a pressure
of over 12 atmospheres in order not to break.

148. A 1. of air is measured at 0°C. and 760 mm.
What volume will it occupy at 740 mm. and + 15.5° C. ?

149. Given 375 cc. of oxygen at -fl7°C. and
375mm., what will be the volume at standard condi-
tions ?

150. Given 3 1. hydrogen at + 15° C. and 752 mm.,
what will be the volume at + 9° C. and 763 mm. ?

151. What is the sp. gr. of oxygen when the barom-
eter stands at 760 mm. and its temperature is 0° C., if
its sp. gr. is 14.7648 when the barometer stands at 745
mm. and its temperature is + 17° C. ?

152. What decrease in pressure will be necessary to
raise a volume of gas measuring over water 400 cc., at
+ 22.5° C. and 748 mm. pressure, to a volume of 440 cc.
under the same conditions?

153. What increase in atmospheric pressure will be
necessary to reduce 200 cc. of a gas, measured in a tube
over water at + 10° C. and 720 mm., to a volume of
100 cc. at + 20° C. in this same tube ?

CHANGES IN VOLUME 41

154. If 98 1. of hydrogen are to be admitted into a
balloon at a temperature of + 20° C. and a pressure of
740 mm., what must be the capacity of the balloon?

155. Of what capacity is that vessel which contains
4 Kg. of oxygen at the temperature of +18° C. and a
pressure of 748.4 mm. ?

156. If 110.08 HI. of hydrogen at 0° C. and 760 mm.
pressure are to be forced into a vessel of 11.2 1.
capacity, under what pressure will the hydrogen be at
this same temperature ?

157. What volume will 0.8 g. of hydrogen occupy
at + 100° C. under the pressure of 750 mm. of mer-
cury ?

158. What pressure will be exerted by 10 g. of car-
bon monoxide, the volume of which is 15 1. at +20° C. ?
(11. = 1.261 g.)

159. At what temperature will 20 g. of nitrous oxide
fill a space of 8000 cc. under twice the atmospheric
pressure? (1 1. =1.969 g.)

160. What is the weight of 51. of oxygen under the
pressure of 800 mm. of mercury at +40° C.?

161. What will be the pressure of 10 g. of marsh
gas, the volume of which is 15 1. at + 30° C. ? (11.=
0.716 g.)

162. If a certain volume of gas weighs 5 g. at + 50° C.
and 300 mm., what should a like volume of the same
gas weigh if measured at -+- 35° C. and 500 mm.?

163. A volume of chlorine measured at + 18° C. and
756 mm. weighs 3 g. If the same volume had been
found at +36° C. and 700 mm., what would it have
weighed? (1 1. Cl = 3.167 g.)

42 PROGRESSIVE PROBLEMS IN CHEMISTRY

164. Carbon dioxide at N.T.P. weighs 1.98 g. per 1.
What would a 1. of it weigh at + 30° C. and 800 mm. ?

165. What is the volume of 20 g. of ammonia at
+ 12° C. and 730 mm. ? (11.= O.T6 g.)

166. If 146 1. of nitrogen at + 17° C. and 974 mm.
are heated to + 51° C., the pressure being decreased to
760 mm., what is the new volume ?

167. What is the mass of 270 cc. of nitrogen meas-
ured over water at 4-8° C. and 768 mm.? (1 1. =
1.25 g.)

168. A gas measured over water has a volume of
64.2 cc. at +18.6° C. and 742.5 mm. Find what the
volume would be at 0° C. and 760 mm.

169. Given 400 cc. of oxygen at standard conditions,
what will -be the volume when measured over water at
+ 20° C. and 755 mm. pressure?

170. Given 100 cc. of a gas measured over water at
4- 25° C. and 745 mm. pressure, what will be the vol-
ume when deprived of moisture ?

171. Given 1000 cc. of oxygen measured over water
at 4- 10° C. and 750 mm. pressure, what will be the
volume at — 10° C. and 770 mm. pressure when de-
prived of moisture?

172. Given 500 cc. of a gas contained in a tube in-
verted over water, and measured at + 10° C. and
765 mm. pressure, what will be the volume under a
change in the atmospheric conditions to + 20° C. and
745 mm. pressure?

173. A vessel of 2000 cc. capacity held 5 g. of a
vapor at the standard conditions of temperature and
pressure. What weight of this vapor at + 10° C. and

CHANGES IN VOLUME 43

750 mm. pressure can be held in this vessel, the capac-
ity considered constant?

174. Reduce the following to standard conditions :
(a) 150 cc. at 603 mm. and + 31° C ; (5) 400 cc. at
876 mm. and - 9° C. ; (c) 500 cc. at 371 mm. and
4-62.17° C. ; (d) 20 cc. at 700 mm. and -14° C. ;
0) 7 1. at 1376 mm. and +13° C.

175. A certain volume of gas is enclosed in a vessel
at 76 cm. pressure and — 20° C. It is then heated to
-f- 40° C. What is the pressure on the sides of the
vessel measured in terms of the atmosphere?

176. If 1000 cc. of chlorine at + 46° C. are in a tube
over mercury which stands in the tube 39 mm. above
that without, the pressure outside being 750 mm., what
would be the volume of the gas under standard condi-
tions?

177. The air in a flexible rubber bag is found to oc-
cupy a volume of 1 ft.3 at 30 in. pressure and +20° C.
If the bag is plunged to a depth of 170 ft. in water, the
temperature of which is + 10° C., what will be its vol-
ume?

178. A vessel full of air at 0° C. is heated to + 80° C.,
when 2 cc. of the air measured at 0° C. are found to
have escaped. How much air was in the vessel before
heating ?

179. A 1. of chlorine at 0° C. and 76 cm. pressure
weighs 3.167 g. If the pressure is decreased to 74 cm.,
what must the temperature be that a 1. of gas may
weigh 2 g. ?

180. If a 1. of nitrogen at 0° C. and 76 cm. pressure
weighs 1.25 g., how many 1. at +25° C. and 74 cm.
pressure will be required to weigh 8 g. ?

44 PROGRESSIVE PROBLEMS IN CHEMISTRY

181. Find the volume of 4450 cc. of carbon dioxide,
measured at standard conditions, at 890 mm. pressure
and + 27° C.

182. A 1. of hydrogen at 760 mm. pressure and 0° C.
weighs 0.0899 g. What will 10 1. weigh at - 20° C.
and 750 mm. pressure?

183. At what temperature, when under a pressure of
75 cm., will 2 1. of gas measured at + 46° C. and 76 cm.
pressure measure 1.8 1. ?

184. A gas at 0° C. and 760 mm. pressure measured
250 cc. What will it measure at -10° C. and 760 mm.
pressure ?

185. A volume of gas in a eudiometer measures 242
cc. The mercury in the tube stands 18 cm. above
that outside. Barometer at 740 mm. ; temperature,
+ 18° C. Reduce to standard volume.

186. A volume of gas in a tube measures 72 cc. The
mercury in the tube stands at the same level as that on
the outside. Barometer 737mm.; temperature +17°C.
What would be the volume under standard Conditions?

187. The volume of gas in a eudiometer measures
68 cc., the level of the mercury in the tube and trough
being the same. The barometer indicates an atmos-
pheric pressure of 739 mm. The temperature is + 20° C.
What would be the volume of the gas at 0° C. and under
760 mm. pressure ?

188. The volume of gas contained in a tube measures 76
cc. The mercury in the tube stands at a height of 17 mm.
Barometer indicates a pressure of 752 mm. The tem-
perature is +9° C. Find volume at 0° C. and 760 mm.

189. If the volume of a mass of gas is 500 cc. at
-f 30° C. and under the pressure of 100 mm., what would

CHANGES IN VOLUME 45

it be under the standard conditions of atmospheric pres-
sure and the temperature 0° C. ?

190. If the volume of a mass of hydrogen is 1000 cc.
at + 100° C. and under the pressure of 800 mm., what
would it be under standard conditions ?

191. If the volume of a mass of oxygen is 400 cc. at
+ 50°C. and under the pressure of 600mm., what
would it be under standard conditions ?

192. If the volume of a mass of air is 4 1. at + 70° C.
and under the pressure of 80cm., what would it be in
cc. under standard conditions?

193. If 500 cc. of chlorine at +60°C. stand in a eu-
diometer over mercury, the level within the tube being
90 mm. above that without and the barometric pressure
being 750 mm., what would be the volume of the gas
under standard conditions ?

194. If 1250 cc. of nitrogen at + 37° C. stand in a
eudiometer over mercury, the level within the tube being
20 mm. below that without and the barometric pressure
being 747 mm., what would be the volume of the gas
under standard conditions?

195. If 780 cc. of air at +28° C. stand in a eudiome-
ter over mercury, the level within the tube being 40 mm.
above that without and the barometric pressure being
750mm., what would be the volume of the gas under
standard conditions ?

196. If J 1. of hydrogen at + 70° C. stands in a eudi-
ometer over mercury, the level within the tube being
50 mm. below that without and the barometric pres-
sure being 745 mm., what would be the volume of the
gas in cc. under standard conditions ?

46 PROGRESSIVE PROBLEMS IN CHEMISTRY

197. If the temperature of a certain volume of air is
increased from —10° C. to -f-30°C., how much must the
pressure be increased to keep the volume constant ?

198. The barometer at 0° C. stands at 750 mm. At
what height will it stand if the temperature rises to
+ 39° C., the pressure remaining the same?

199. If a quantity of gas, measured at 0° C. and 75 cm.
pressure, is subjected to a pressure of 775 mm., how much
must the temperature be increased that the volume may
remain the same ?

200. A sample of moist air, confined over water at
+ 15° C. and 760 mm., occupies 15 cc. It is mixed with
20 cc. of hydrogen, the mixture is exploded, and suffers
a contraction of 9.5 cc. What would be the volume
of the oxygen it contained if measured dry at 0° C. and
760 mm. ?

201. To how many atmospheres pressure must a 1.
of gas measured at 76 cm. pressure and — 20° C. be
subjected to be condensed to J a 1. when the tempera-
ture is 4-40° C.?

202. A volume of gas which measures 2 1. at 742 mm.
was afterwards found to measure 2163 cc. What was
the height of the barometer at the time of the second
reading?

203. Some hydrogen under 900 mm. pressure and
-f 20° C. occupies 300 cc. What volume will it occupy
at +109° C. under 600mm. pressure?

204. Find the pressure on the gas in a tube when the
mercury inside and outside the tube are the same, and
the temperature is +25°C. and the barometer stands
at 760 mm.

CHANGES IN VOLUME 47

205. A 1. flask was filled with air at — 10° C. and
750mm. pressure. If the barometer rises to 760mm.,
to what temperature must the flask be raised to drive
out ^ the air that was in it when it was filled ?

206. The gas enclosed in a piston tube is compressed
to i| its original volume measured at 76 cm. pressure,
and the temperature is raised from +10° C. to +130° C.
What is the pressure on each cm.2 of the piston?

207. When 1000 cc. of a gas were measured at -f 16° C.
and 750 mm., and the volume was increased to 1120 cc.
by warming, the final pressure read 740mm. What
was the final temperature of the gas?

208. What decrease in temperature will be necessary
to reduce 400 cc. of a gas at + 20°C. and 765mm. to
a volume of 300 cc. at 750 mm. ?

209. If 1 g. of gunpowder yields, on explosion at 0° C.
and 760 mm., 288 cc. of gases, what volume would be
occupied at + 2200° C., which is reached at the moment
of exploding?

210. What change in* temperature will be necessary
to bring a volume of gas, measuring 5600 cc. at + 10°
C. and 745 mm. pressure, to a volume of 600 cc. at this
same pressure?

CHAPTER V

Volumes of Gases from Weights — Specific Gravity and
Vapor Density

1. Calculate the density, weight of 11., and sp. gr.
of the following gases :

C2H2, CO, C2H4, CH4, C3H8,

NH3, COS, HBr, NO, C3H6,

AsH3, COC12, HC1, N2, SO2,

Br2, C12, HF, N2O, H2O.

C4H10, C2N2, HI, 02,

CO2, C2H6, H2S, PH3,

2. Find the weight of 10 1. of NO. What volume
will 5 g. of the gas occupy ?

3. Find the weight of the following volumes of dry
air at standard conditions : (a) 20 cc. ; (5) 300 cc. ; (c)
731.; (d)30mmA

4. Determine the weight, at 0° C. and 760 mm., of
1 1. of each of the following gases, on the assumption
that they can exist in the gaseous condition at the
standard temperature and pressure :

Water, Trihydrogen phosphide,

Hydrogen chloride, Alcohol,

Ammonium chloride, Nitrogen monoxide,

Carbon dioxide, Nitrogen tetroxide,

Carbon disulphide, Mercuric chloride.

48

VOLUMES, SPECIFIC GRAVITY, VAPOR DENSITY 49

5. What is the weight of 1500 cc. of a gas at the
standard pressure of 760 mm. and temperature of zero,
if its sp. gr. referred to hydrogen is 14?

6. Under a pressure of 745 mm., 1500 cc. of chlorine
weigh 4.67 g. What is the weight of 1 1. under
standard pressure ?

7. The formula for ethane is C2H6. Calculate the
sp. gr. of its vapor (a) compared with hydrogen ; (5)
compared with air.

8. Two 1. of hydrogen sulphide weigh 3.0442 g. ;
what is its sp. gr. referred to air ?

9. The molecular weight of bromine is 160 ; what
is the sp. gr. ?

10. What will be the volume of phosphorus vapor
obtained from 3 g. of solid phosphorus at + 420° C. ?

11. The density of carbon monoxide is 14 ; what is
the weight of 1 1. ?

12. How many 1. of hydrogen in 2.7 g.?

13. How many 1. of chlorine in 7.3 g.? How many
cc.?

14. What volume of HC1 in 50 g. ?

15. If 2 1. of chlorine weigh 6.3 g., find the density
of chlorine.

16. If 5 1. of CO2 weigh 9.9 g., what is its density?

17. If 3 1. of mercury vapor weigh 26.9 g., compute
the vapor density of mercury.

18. Calculate the weight of 1 1. of each of the following
gases : (#) chlorine ; (ft) nitrogen ; (c) sulphur dioxide ;
(d) nitrous oxide ; (0) nitric oxide ; (/) ethane ; (#)
butane ; Qi) hydrogen chloride ; (i) carbon monoxide ;
(/) carbon dioxide ; (&) marsh gas ; (7) phosphine.

50 PROGRESSIVE PROBLEMS Itf CHEMISTRY

19. What do 100 1. of nitrogen weigh?

20. Nitric oxide is 15 times as heavy as hydrogen ;
how many times is it heavier than air ?

21. Calculate the density (referred to air) of propane.

22. Calculate the density (referred to air) of sulphur
dioxide.

23. The vapor of silicon chloride is 5.936 times as
heavy as air. Find its density compared with hydrogen.

24. A vessel holding 30.8 g. of carbon dioxide at
+ 10°C. and 740 mm. pressure is to be brought to a
temperature of -f 50° C. and a pressure of 750 mm.
What weight and volume of carbon dioxide will be
lost?

25. What is the weight of 6.594 1. of oxygen at
+ 40° C. and 740 mm. pressure ?

26. The relative density of carbon dioxide is 21.83;
what is the relative density of this gas upon the oxygen
standard ?

27. Find the density (air = 1) of the following : car-
bon monoxide ; carbon disulphide ; sulphur dioxide ;
boron trifluoride ; phosphorus pentafluoride.

28. Find the volume at standard conditions of 1 g.
H; 16 g. O; 14 g. N; 35.5 g. Cl ; 80 g. Br vapor;
9 g. steam; 18.25 g. HC1; 22 g. CO2; 8 g. CH4; 32
g. S02; 14 g. CO. *"

29. What weight of arsenic is contained in a 1. of
cacodyl oxide vapor, [(CH3)2As]2O, measured at
+ 500°C.?

30. What is the volume of 3.0571 g. of a gas, if its
sp. gr. referred to air is 0.591?

VOLUMES, SPECIFIC GRAVITY, VAPOR DENSITY 51

31. A hall is of such dimensions that it contains
50T.0912 Kg. of air at 0° C. and 760 mm. What is the
capacity of the hall measured in m.3?

32. Determine the mass of 750 cc. of nitrogen meas-
ured over water at + 20° C. and 780 mm.

33. If 545 cc. of nitrogen are measured over water at
+ 22° C. and 748 mm. pressure, what weight will they
contain of the dry gas ?

34. What volume will 2.2 g. of oxygen at +20°C.
and 770 mm. pressure occupy when transferred to a
vessel inverted over water ?

35. What volume will 1 g. of hydrogen measured at
standard conditions occupy when transferred to a vessel
over water at 0° C. and 760 mm. pressure ?

36. What volume will 310 g. of carbon dioxide oc-
cupy when contained in a vessel over water at -f-20°C.
and 742.4 mm. pressure ?

37. What volume will 1 g. of oxygen occupy over
water at -f- 30° C. and 756.5 mm. pressure ?

38. At what temperature will 8 g. of oxygen under
a pressure of 760 mm. occupy a volume of 11.1 1. at
this same pressure ?

39. Find the mass of 250 1. of chlorine at -7°C.
and 886 mm.

40. The sp. gr. of oxygen under standard conditions
is 1.1; what is the sp. gr. when the barometer stands
at 745 mm.?

41. The sp. gr. of oxygen referred to hydrogen is 16
at 0°C.; what is its sp. gr. when its temperature is

+ 27°C.?

52 PROGRESSIVE PROBLEMS IN CHEMISTRY

42. If the sp. gr. of a gas is 22 at 0° C., what will be
itssp. gr. at + 81.9°C.?

43. Calculate the weight of the following gases at
standard pressure and temperature : 2 1. of hydro-
chloric acid gas ; 1500 cc. of hydrogen sulphide ; 250
cc. of chlorine ; 5 1. of ethane (C2H6).

44. The density of a substance referred to air is 3.2.
What is the density referred to hydrogen ? What will
be the volume occupied by 10 g. of the substance at
+ 20°C. and 752 mm.?

45. How many g. do 10 1. of hydrogen phosphide
weigh ?

46. A 1. of hydrogen under standard conditions
weighs 0.09 g. What is the weight of a 1. of ozone
under the same conditions?

47. A gas has the formula C3H8. Is it lighter or
heavier than air ? Find the sp. gr.

48. Calculate the sp. gr. of cyanogen and the weight
of 31.

49. Determine the mass of 7.3 1. marsh gas, 8 1. of
ethylene, and 16 g. choke damp, measured at 760 mm.
and 0° C.

50. Find the weight at + 182° C. and 770 mm. oc-
cupied by 50 1. of (a) HF, (5) HI, (e) HC1.

51. What mass of nitrogen will measure 1000 cc. at
+ 15°C. and 765 mm.?

52. Find under standard conditions the weight of 1 1.
of CO, CO2, and CH4.

53. Find the mass of 5.6 1. of CO.

54. What space will 125 g. of iodine vapor occupy
at + 1900° C. and 794 mm. ?

VOLUMES, SPECIFIC GRAVITY, VAPOR DENSITY 53

55. What is the volume of 20 g. of carbon dioxide
at the standard temperature and pressure?

56. What is the volume of 82.88 g. of the vapor of
ethyl ether at the temperature of + 147° C. and under
a pressure of 740 mm. ?

57. What weight of carbon does 1 1. of CO2 contain ;
11. CO?

58. What is the weight of 5 1. of ethyl alcohol vapor
having a temperature of + 127° C. and under a pres-
sure of 750 mm. ?

59. What is the volume of a Kg. of carbon monoxide
at 0° C. and 760 mm. ?

60. What is the volume of 225 g. of hydrogen sul-
phide at 0° C. and 760 mm. ?

61. Calculate the volume, at the standard tempera-
ture and pressure, of a Kg. of the following gases :
carbon monoxide ; ethylene ; hydrogen sulphide ; oxy-
sulphide of carbon ; methyl hydride ; bromine ; water.

62. What volume will 49.63 g. of chlorine occupy at
standard conditions?

63. What is the volume occupied by 8.8 g. of carbon
dioxide at +12° C. and 752 mm. pressure?

64. Find the volume of 10 g. N2O ; 13 g. NO ; 7 g.
N203; 6g. N204.

65. What volume of hydrogen is contained in 6 cc.
of NH3?

66. Find the weight of 500 cc. of H ; 250 cc. of Cl;
700 cc. of CH4 ; 130 cc. of PH3.

67. Find the volume at +41° C. and 785 mm. oc-
cupied by O) 66 g. CO2; (6) 96 g. AsH3.

54 PROGRESSIVE PROBLEMS IN CHEMISTRY

68. The weight of 1 1. of aqueous vapor at 0° C. and
760 mm. is 0.8045 g; what is its relative density?

69. Calculate the relative density of mercury vapor,
1 1. of which at standard conditions weighs 8.87 g.

70. A 1. of NH3 weighs 0.762 g. at 0° C. and
760 mm. Find (a) its vapor density ; (&) its sp. gr.

71. Find the volume at +41° C. and 78.5 mm. oc-
cupied by (a) 66 g. CO2; (6) 96 g. stibine.

72. What is the weight of 573 cc. of air at + 30° C.
and 769 mm. ?

73. What is the weight of a m.3 of hydrogen at the
standard temperature and twice the standard pressure?

74. What weight of hydrogen and of bromine in
1 1. HBr at + 60° C. and 760 mm. ?

75. How many times heavier than a 1. of hydrogen is
(a) one of air ; (5) one of oxygen ; (c) one of chlorine ;
(cT) one of nitrogen ?

76. Find the weight of 300 cc. NH3.

77. How many g. in 3000 cc. of H2S, measured at
+ 16°C. and 780 mm.?

78. Determine the mass of 34 1. of (a) NH3;
(5)S02; (OSiF4; (<OCaHa.

79. Find the volume at -f- 10° C. and 761 mm. oc-
cupied by (a) 3 g. H2S; (6) 13 g. PH3; (*) 2 g.
SbH3.

80. The weight of 2.3 1. of oxygen at 0° C. and
760 mm. is 3.2885 g. Find the sp. gr. referred to
air.

81. Three 1. of marsh gas weigh 2.15 g. What is
its sp. gr., hydrogen being the standard?

VOLUMES, SPECIFIC GRAVITY, VAPOR DENSITY 55

82. At 760 mm. pressure, what is the weight of 1 1.
of acetylene at 0° C. ; of hydrogen sulphide at 0° C. ;
of steam at +150° C. ; of water at +4° C. ; of sul-
phuric acid, sp. gr. 1.84; of sulphur at -f- 500° C.; of
bromine at + 4° C. ; of bromine at -f- 400° C. ; of iodine
at + 500° C. ; of iodine at + 1500° C, ?

83. What volume is occupied by 177.5 g. of chlorine?

84. Find the number of 1. occupied by 64 g. of sul-
phur dioxide ; occupied by 32 g. of oxygen ; occupied
by 2 g. of hydrogen ; occupied by 16 g. of methane.

CHAPTER VI

Weights from Equations

1. How much KC1O3 must be decomposed to yield
20 g. of oxygen? What weight of KC1 will be left?

2. How many g. of CO2 will be produced by burn-
ing 100 g. of carbon in oxygen?

3. How many g. of hydrogen will result from
placing 46 g. of sodium on water ?

4. How many g. of acetylene gas will be generated
by 750 g. of pure calcium carbide ?

5. How many Ib. of water would be needed to
slake 15 Ib. of CaO?

6. In the changing of 500 Ib. of Ca(OH)2 in mortar
to CaCO3, how many Ib. of water are produced and
how many 1. of CO2 are needed?

7. How much plaster of Paris results from heating
100 Kg. of gypsum?

8. How many Ib. of CaO and how many m.3 of
CO2 would be formed by heating 5 tons of limestone?

9. From 30 tons of sodium nitrate, how much nitric
acid (80% HNO3) can be produced? How much sul-
phuric acid is necessary to make it ?

10. How much CO will result on heating 70 g.
of H2C2O4 with concentrated H2SO4?

56

WEIGHTS FROM EQUATIONS 57

11. If 100 g. H2C2O4 are heated with H2SO4 and the
gases are passed through a solution of NaOH, what
volume of CO and what weight of Na2CO3 will result ?

12. What weight of HC1 cau be made from 50 g. of
NaCl?

13. What weight of arsenic would be obtained by
reducing 157 g. of arsenic trioxide with charcoal ?

14. If a candle consists of 85 % of carbon and 15 % of
hydrogen, what weights of carbon dioxide and water
will be formed when 25 g. of the candle burn ?

15. To what weight of nitrous acid do 100 g. of
nitrous anhydride correspond ?

16. How much nitrogen peroxide is obtainable from
200 g. of nitric acid?

17. What weight of copper nitrate is obtainable from
50 g. of nitric acid and copper?

18. How much nitrogen peroxide can be made from
100 g. of nitric oxide ?

19. How much hydrocyanic acid is obtainable from
70 g. of potassium cyanide ?

20. How much cyanogen is obtainable from 200 g. -of
mercuric cyanide ?

21. What weight of carbon dioxide will 300 g. of
calcium carbonate yield on treatment with an acid?

22. What weight of NaOH and HC1 will be needed
to produce 75 g. of NaCl?

23. If 100 Kg. of "fool's gold" are heated (a) in
a tube, (5) in the air, what are the weights of the sub-
stances produced in each case ?

24. What weight of Na2CO3 will result from heating
500 g. of sodium dicarbonate ?

58 PROGRESSIVE PROBLEMS IN CHEMISTRY

25. What weight of washing soda would be needed
to furnish 125 g. of anhydrous Na2CO3?

26. What weight of nitric acid will be produced by
heating 75 g. of Chili saltpeter with an excess of con-
centrated sulphuric acid ?

27. What weight of sulphuric acid and sodium ni-
trate should be taken in order to obtain 215 g. of nitric
acid?

28. If 78 g. of copper nitrate is decomposed by con-
centrated sulphuric acid, what weight of nitric acid and
what weight of copper sulphate will be formed?

29. If copper and nitric acid react, what weight of
metallic copper should be taken, if one Kg. of copper
nitrate is to be formed?

30. What weight of nitrogen tetroxide (N2O4) will
result when 3300 cc. of nitric oxide (NO) is brought into
contact with an excess of oxygen ?

31. What weight of N2O will be formed by heating
50 g. of NH4NO3? How many g. of water will be
formed?

32. What weight of NH4NO3 will be taken to yield
upon heating 1 1. of N2O ?

33. What weight of NH3 will result upon decompos-
ing 50 g. of NH4C1 with slaked lime?

34. What weight of potassium and what weight of
chlorine are contained in 17 g. of potassium chlorate?

35. How much potassium chloride would be formed
by heating 35 g. of potassium chlorate ?

36. How much BaO2 must be heated in order to ob-
tain 14 g. of oxygen?

WEIGHTS FROM EQUATIONS 59

37. If potassium chlorate costs 80 cts. per Kg., what
will be the cost of enough to make 500 g. of oxygen ?

38. What weight of sodium will be necessary to de-
compose 15 g. of water? What weight of hydrogen
will be formed ?

39. What weight of sodium would be needed to pro-
duce, by the decomposition of water, 1 1. of hydro-
gen?

40. What weight of oxygen can be obtained by heat-
ing 18 g. of mercuric oxide ?

41. How much mercuric oxide must be heated in
order to obtain 2 g. of oxygen?

42. With what weight of mercury will 9 g. of oxy-
gen unite to form mercuric oxide?

43. To obtain 15 g. of iodine, how much manganese
dioxide, potassium iodide, and sulphuric acid will be re-
quired?

44. What weight of hydrofluoric acid would be
evolved by treating 36 g. of calcium fluoride with sul-
phuric acid?

45. How much common salt will be needed to yield
10 g. of chlorine on treatment with manganese dioxide
and sulphuric acid?

46. What weight of zinc sulphate will be formed upon
treating 13 g. of zinc with sulphuric acid?

47. How much manganese dioxide will be required
to liberate 13 g. of chlorine from hydrochloric acid?

48. What weight of chlorine will result from the
electrolysis of a solution containing 65 g. of potassium
chloride ?

60 PROGRESSIVE PROBLEMS IN CHEMISTRY

49. An ore contains 62.38% of arsenopyrite (FeAsS).
What weight of white arsenic could be obtained by
heating 500 Ib. of the ore ?

50. What weights of mercury and sulphur dioxide
could be obtained from 1 ton of an ore carrying 53.78%
of cinnabar?

51. What weight of aluminum oxide is contained in
100 Ib. of potassium alum?

52. What weight of aluminum hydroxide will be pro-
duced when a solution containing 35 g. of potassium alum
is precipitated with ammonium hydroxide?

53. An ore contains 23.46 % of stibnite, Sb2S3 ; what
is the °/0 of antimony in the ore ?

54. How many Ib. of calcium carbide will be neces-
sary to produce 1300 g. of acetylene?

55. How many Ib. of zinc may be obtained from a
ton of an ore containing 17.3 % of zinc carbonate?

56. What weight of silicon tetrafluoride could be ob-
tained by treating 430 g. of silica with hydrofluoric
acid?

57. If 275 g. of silica is fused with an excess of po-
tassium carbonate, what weight of potassium silicate
(K2SiO3) will result?

58. From 1500 Ib. of salt how many Kg. of sodium
carbonate can be obtained by the Leblanc process ? How
much charcoal and how much limestone will be re-
quired ?

59. What weight of calcium sulphide will be pro-
duced in the manufacture of 1 ton of dry sodium car-
bonate by the Leblanc process?

WEIGHTS FROM EQUATIONS 61

60. What weights of salt, ammonia, and carbon dioxide
will be necessary to produce 1 ton of NaHCO3 by the
Solvay process?

61. In a case of poisoning, 11.73 g. of arsenic tri-
sulphide were found ; to how much arsenic trioxide does
this correspond?

As2S3 + 9 O = As2O3 + 3 SO2.

62. If I wish to make ferrous sulphide, how many g.
of sulphur should I mix with 56 g. of iron filings, and
how much ferrous sulphide should result ?

63. How much hydrogen and how much zinc chloride
should result from treating 25 g. of zinc with a sufficient
quantity of hydrogen chloride ?

64. What weight of oxygen is needed to burn a dia-
mond which weighs half a gr. ? What will the CO2
formed weigh ?

65. How much sulphuric acid will neutralize 50 Ib.
of sodium hydroxide ?

66. How much lead is needed to form 2 Kg. of lead
nitrate ?

67. How many g. of HNO3 will 140 g. of NH4NO3
give ?

68. How many g. of iodine in 166 g. of KI ?

69. How many tons of pyrite containing 39.2%
of available sulphur are needed to make 4000 tons of
sulphuric acid of sp. gr. 1.730 containing 80% pure
H2SO4 and allowing for no losses ?

70. What weight of iron rust may be obtained with
a supply of 10 g. of oxygen ?

71. How much MnO2 is needed to make 125 g. of
chlorine from HC1 ?

62 PROGRESSIVE PROBLEMS IN CHEMISTRY

72. What weight of ammonium chloride, when acted
upon by calcium hydroxide, is required to produce 17
g. of ammonia, and what weight of calcium chloride is
formed at the same time ?

73. How much " laughing gas " may be made from
80 g. of NH4N03?

74. How much KI is needed to prepare 63.5 g. of
iodine ?

75. How much K2CO3 and Ca(OH)2 will give a Kg.
of KOH ?

76. Find the weight of Hg and O from decomposing
10 g. of HgO.

77. How many g. of NH4NO3 must be used to pro-
duce 20 g. of N2O ?

78. How much phosphorus is there in 1 ton (2000
Ib.) of bone ash?

79. What weight of zinc will be required to decom-
pose 10,000 Ib. of sulphuric acid ?

80. What weight of zinc and of sulphuric acid is
necessary to prepare 50,000 1. of hydrogen at + 31° C.
and 758 mm. pressure ?

81. One Kg. of phosphorus is converted into phos-
phoric anhydride. What weight of phosphoric acid
will this yield ?

82. Find the g. of each component in 76 g. of HNO3.
How many g. of nitric oxide can be set free by the
action of 252 g. of HNO8 on copper ?

83. What weight of sulphur is contained in 100 g. of
pyrite ?

84. How much silver is contained in 100 g. of an
impure specimen of silver chloride which is 33 % sand ?

WEIGHTS FROM EQUATIONS 63

85. What weight of oil of vitriol of 97 % can be
made from 1000 Kg. of sulphur ?

86. What weight of oxygen is necessary to burn the
sulphur derived from the decomposition of 1 g. of
sulphurous anhydride, and what is the weight of the
product ?

87. Calculate the weight of tin and hydrochloric acid
necessary to produce 16 g. of hydrogen.

88. How much sodium carbonate and calcium hy-
droxide are needed to make a Kg. of sodium hydroxide ?

89. Find the weight of each of the products formed
by the complete combustion of 52 g. of turpentine.

90. A certain weight of MnO2 is heated till decom-
posed; if the residue weighs 149 g., what weight of
oxygen was evolved ?

91. How many g. of CaCO3 must be used to prepare
22 g. of carbon dioxide by the action of HC1 ?

92. If 2 g. of silver are dissolved in nitric acid
and half a g. of pure, dry sodium chloride is added,
what percentage of the silver remains in solution ?

93. How much potassium, by its action upon water,
is required to furnish 2J g. of hydrogen ?

94. Find the number of g. of HC1 that can be set
free by the complete action of 10 g. of H2SO4 on
common salt.

95. The ammonia obtained from 20 Kg. of ammo-
nium chloride is united with sulphuric acid to form the
neutral salt. What is the weight of the product ?

96. How many Ib. of limestone are needed to pro-
duce 1 ton of quicklime ?

64 PROGRESSIVE PROBLEMS IN CHEMISTRY

97. To obtain 15 g. of bromine, how much MnO2,
KBr, and H2SO4 should be used ?

98. What weight of a gas mixture known as " water
gas" can be obtained from 24 Ib. of carbon and the
necessary steam ?

99. What is the weight of BaO in 1.5 g. of barium
carbonate?

100. How many g. of silver will 5 g. of sodium bro-
mide precipitate from a solution of silver in nitric acid ?

101. If a solution containing 50 g. of lead nitrate
is precipitated by hydrogen sulphide, what will be the
weight of the precipitate ?

102. If a solution containing 50 g. of copper sulphate
is precipitated by hydrogen sulphide, what will be the
weight of the precipitate ?

103. How much sulphuric acid could be produced
from the sulphur dioxide arising from the combustion
of 1 ton of sulphur? .

104. How much sulphuric acid could be produced
from the sulphur dioxide arising from the combustion
of 1 ton of pure pyrite ?

105. If 100 cc. of a solution of barium chloride that
contains 20 g. of the salt in 1 1. is precipitated by sul-
phuric acid, what weight of BaSO4 will be formed ?

106. How much potassium chlorate can be made
from 150 g. of potassium hydroxide according to the
following reaction :

6 KOH + 3 C12 = KC1O3 + 5 KC1 + 3 H2O ?

107. How much AgNO3 can be obtained from 15 g.
of Ag, and how much H2O and how many g. of NO
will be formed ?

WEIGHTS FROM EQUATIONS 65

108. AsH3 is decomposed into its elements. How
many mg. of each element from 550 cc. of AsH3 ?

109. How much hydrogen potassium carbonate is
required to give 1.98 g. of carbon dioxide ?

110. How much manganese dioxide is required to
charge a wedge-shaped gas bag, 1 m. high and wide
and | m. basal thickness, with oxygen at +15° C.?

111. One g. of Ca(OCl)2 is boiled with water and
CuO. What weight of oxygen is evolved ?

112. A solution contains 30 g. of silver nitrate. How
much common salt is required to decompose the silver
nitrate, and how much silver chloride is produced ?

113. If 1 Kg. of HNO3 is needed, what weights of
materials are required to make it ?

114. CHKO2 (potassium formate) + KOH = K2CO3
+ H2. In the above equation, if 1 Kg. of CHKO2 is
used, find the weight of gas evolved.

115. How much hydrochloric acid can be obtained by
treating 1 Kg. of common salt with sulphuric acid?
How much sulphuric acid will be needed ?

116. A piece of potassium is thrown on water; the
KOH will just neutralize 50 cc. of a solution of
H2SO4 containing 98 g. Find the weight of potassium
used.

117. If 2 g. of Ag2O are thrown into hydrogen perox-
ide, what weight of gas is evolved ?

118. If 200 Ib. of nitre and enough H2SO4 are heated
together, what weight of HNO3 is given off?

119. What weight of CO2 is needed to convert
50 tons of "soda" crystals into dicarbonate of
soda?

66 PROGRESSIVE PROBLEMS IN CHEMISTRY

120. A diamond weighing 0.3 g. is burned in a jar
of oxygen. How much CaCO3 would be formed by
shaking the contents of flask after combustion with lime-
water ?

121. A certain amount of H2SO4 requires 10 g. of
BaCl2 to precipitate it completely. Find the weight of
acid used.

122. How much water must be added to 100 g. of
P2O6 to form orthophosphoric acid ?

123. A copper coin liberates from sulphuric acid
22 g. of SO2. Find the weight of the coin.

124. How much carbon heated in the air will give
14 g. of C02?

125. 13 g. C6H6 is burned in air. Find the weight of
oxygen used and the weight of the gaseous products.

126. What weight of calcium carbide (3 C + CaO =
CaC2 + CO) will 600 Ib. of lime make ? How much
carbon is needed ?

127. Hydrogen is passed over 2.48 g. of heated CuO
and the weight is 2.24 g. The water formed weighs
0.27 g. Calculate the weight of H and O.

128. How much KC1 can be obtained from 200 g.
KC1O3 containing 12% of impurities? Find weight of
oxygen given off.

129. Iron dissolved in hydrochloric acid gives 66 cc.
of hydrogen. Find the weight of iron used.

130. Water is decomposed and the oxygen is burned
with pure carbon, giving 44 g. of CO2. How much
water was used?

131. One Kg. of NaNO3 is treated with oil of vitriol.
Find the weight of aqua fortis produced.

WEIGHTS FROM EQUATIONS 67

132. How much fluorspar will be needed to unite
with 100 g. of H2SO4?

133. If 10 g. of carbon are heated with 67 g. of CO2,
what weight (a) of CO is formed; (6) of residue, if
any?

134. vTo get 76 Kg. of oxygen, how much air is
needed?

135. In 300 Ib. of bone ash are contained : (a) how
many Ib. of oxygen ; (&) how much calcium ?

136. If the bones of a man weigh 26 Ib. and contain
60 % Ca3(PO4)2, find (a) the weight of phosphorus;
(5) the value of the skeleton to make phosphorus pent-
oxide at |3 a pound.

137. If 4 Kg. of Na2CO3 are heated with carbon,
what is the weight of sodium produced and of carbon
used?

138. How many g. of oxygen and of hydrogen can
be obtained by the decomposition of 27 g. of water?

139. How many g. of oxygen can be obtained by the
decomposition of 100 g. of mercuric oxide?

140. If 3 g. of urea are warmed with KNO3 and hy-
drogen sulphate, what weights of gases are given off?
CON2H4 + O3 = N2 + 2 H2O + CO3.

141. Calculate the weight of iron that would be dis-
solved by 100 g. of a solution of hydrochloric acid con-
taining 20 % by weight of the gas.

142. Calculate the weight of zinc sulphate that would
be produced by dissolving 10 g. of zinc in sulphuric
acid.

143. How much iodine can be obtained from 236 g.
of potassium iodide ?

68 PROGRESSIVE PROBLEMS IN CHEMISTRY

144. What weights of iron, iodine, and K2CO3 are
needed to make 347 g. of KI ?

145. What is the weight of potassium chlorate
yielded by the chlorine evolved from 100 tons of man-
ganese ore containing 60 % of the dioxide?

146. What weight of potassium bromate can be
obtained by neutralizing 520 g. of bromine with pot-
ash?

147. A manufacturer of bleaching powder requires
10 tons of chlorine. How much salt, manganese ore
containing 59 % of the dioxide, and sulphuric acid con-
taining 58 % of real acid will he need?

148. What weight of MnO2, when heated, will yield
1 g. of oxygen?

149. If 2000 g. Cu are heated in air, what weight of
oxygen will be used and what weight of CuO will be
produced ?

150. I require 2 Kg. of oxygen ; how much (a) mer-
curic oxide, (5) potassium chlorate, and (<?) manganese
dioxide, and (c?) sulphuric acid shall I need?

151. How much KMnO4 is needed to furnish 1 Ib. of
oxygen ?

152. If 132.74 Kg. of hydrogen are needed to inflate
a balloon, what weight of zinc and sulphuric acid will
be required to produce this quantity of gas ?

153. Since 77 % of the weight of the air, freed from
moisture and CO2, consists of nitrogen, calculate the
weight of (a) metallic copper, and (5) of phosphorus
required to abstract the oxygen from 1 Ib. of air.

154. In burning 17 g. of alcohol, find the weight of
the products.

WEIGHTS FROM EQUATIONS 69

155. How much NH4NO3 would produce enough N2O
for the combustion of 36 g. of carbon ?

156. How much nitrogen can be produced by the
combustion of NH3 produced by the action of 15 g. of
NH4C1 on NaOH ?

157. How much K2Cr2O7 will be needed to convert
10 g. of FeCl2 to FeCl3 ?

158. How many g. of acetic acid are required to
neutralize 6 g. of K2CO3?

159. If a solution contains 30 g. KI, how much chlo-
rine would be needed to liberate all the iodine, and how
much KC1 would result ?

160. What weight of SnCl2 is needed to precipitate
completely the gold in 200 g. of AuCl3 ?

161. If 100 g. MnO2 are treated with HC1 in excess,
what weight of chlorine is evolved ? If treated with
enough NaCl and H2SO4, how much chloride would be
necessary ?

162. If 300 g. of cinnabar are heated, (#) how much
oxygen is needed ; (6) what weight of mercury is left ?

163. If 63 g. of lead are heated, how many g. of PbO
are produced ?

164. If 100 g. of copper and 100 g. of sulphur are
heated together, what substances will be found after
combination and how much of each ?

165. If 32 g. Cu, 103 g. Pb, 12 g. Mg, and 25 g. Fe
are each heated in the air till they cease to gain in
weight, how many g. will each gain ?

166. How much iron is needed to throw down all the
copper in a CuSO4 solution containing 160 g. and what
weight of FeSO4 will be formed ?

70 PROGRESSIVE PROBLEMS IN CHEMISTRY

167. Calculate the weight of air required to burn a
ton of coal possessing the following percentage com-
position : carbon, 88.42 ; hydrogen, 5.61 ; oxygen,
5.97.

168. What weight of potassium chlorate is needed to
furnish oxygen sufficient to burn the hydrogen evolved
by the action of water on 200 g. of calcium ?

169. If 100 g. of pure iron are burnt in excess of (a)
oxygen and (6) chlorine, what is the weight of oxide
and chloride produced ?

170. How much nitre and sulphuric acid shall I need
to prepare nitric acid enough to neutralize exactly 5 Ib.
of chalk ?

171. How much pure zinc will be required to prepare
1 Kg. of hydrogen ?

172. What weights of NaOH and H2SO4 are needed
to produce 100 g. of Na2SO4?

173. How many g. of sulphuric acid and of nitre are
required to make 250 g. of nitric acid ?

174. How much crystallized microcosmic salt must be
ignited to furnish a g. of sodium metaphosphate?

175. What weights of copper and sulphuric acid are
needed to yield 30 g. of sulphurous acid at the stand-
ard temperature and pressure?

176. What weight of iron is contained in 10 tons of
pyrite?

177. What weight of silver chloride will be formed by
the reaction of 0.2008 g. of sodium chloride with silver
nitrate in solution?

178. How many tons of coke containing 97 % of
carbon are required to reduce 388 tons of hematite ?

WEIGHTS FROM EQUATIONS 71

179. How much carbon would be necessary to reduce
9 g. of copper oxide ?

180. How much sulphuric acid (80%) should be
procurable from 5 tons of pyrite which carries 44 % of
sulphur?

181. Suppose a glass had the formula Na2O, CaO,
6 SiO2, how much sodium carbonate and limestone would
be necessary to make 250 Ib. ?

182. If monazite sand contains 4 % of ThO2, how
many tons of the sand would be necessary to produce
24,000,000 mantles, if each mantle weighs 6 g. ?

183. How many Ib. of pig iron containing 95% Fe
can be made from 2000 Ib. Fe2O3?

184. How much copper oxide would be used and cop-
per obtained in preparing 3.2 g. of water?

185. How much carbon dioxide and disulphide, re-
spectively, can be produced from 4 Ib. of pure char-
coal?

186. How much barium dioxide is necessary to make
5 Ib. of a* 4 % solution of hydrogen dioxide ?

187. How much lime is theoretically obtainable from
9 tons of limestone which is 97 % pure?

188. What weight of sodium chloride, when treated
with sulphuric acid, will produce 100 g. of sodium sul-
phate ?

189. What weight of sulphuric acid can be manufac-
tured from a ton of pyrite ?

190. What mass of water will be needed to convert
142 g. of P2O5 into (a) hydrogen orthophosphate ;
(5) hydrogen pyrophosphate ; (<?) hydrogen metaphos-
phate ?

72 PROGRESSIVE PROBLEMS IN CHEMISTRY

191. What weight of KMnO4 will be needed to con-
vert 139 g. of FeSO4, 7 H2O into the ferric condition ?

192. We need 4711 g. common alum ; what weight
of "alumina" is needed?

193. How much of each material would be needed to
produce 502 g. of "manganese alum"?

194. How much water is necessary to convert 55 g. of
P2O3 into hydrogen phosphite?

195. What mass of oxygen can be obtaine.d by heat-
ing («) 24 g. KC1O3; (5) 174 g. MnO2 ; (c) 49 g. KC1O3
and MnO2; (d) 100 g. HgO ; (e) 200 g. Cu(NO3)2?

196. How many g. of commercial HNO3 (containing
68% HNO3) will be needed to decompose (a) 100 g.
marble ; (6) 100 g. Na2GO3 ?

197. What weight of hydrogen can be obtained by
the action of 112 g. KOH on potassium formate?

- 198. Find weight of oxygen needed to burn 150 g.

of CS2.

199. How many g. arsenic are needed to make 200 g.
of arsenibus oxide ?

200. What weight of magnesium oxide will be pro-
duced by burning 0.5 g. of magnesium ribbon?

201. What weight of oxygen will be obtained by
heating 26 g. of potassium chlorate ?

202. What weight of quicklime can be obtained from
1800 Ib. of limestone ?

203. How much carbon dioxide may be obtained
from 22 g. calcium carbonate?

204. Ten g. of sodium hydroxide are dissolved in
water, a volume of hydrochloric acid containing 15 g.

WEIGHTS FROM EQUATIONS 73

of hydrogen chloride is added, and the mixture is
evaporated to dryness. Of what does the residue con-
sist and what is the weight of each constituent ?

205. What weight of silver nitrate could be obtained
by dissolving a ten-cent piece, weighing 2.44 g. and
containing 90 % silver, in dilute nitric acid and evapo-
rating ?

206. Assume that "thermit" contains 75% iron
oxide ; how much of the mixture would be required to
produce 6 Ib. of metallic iron?

207. How many pailf uls of water, 12 Kg. each, would
be required to slake 250 Ib. of quicklime ?

208. How many Ib. of pure calcium cyanamide would
be required to produce 40 Ib. of ammonia?

209. If 80 g. of potassium chlorate are decomposed,
the oxygen collected, and magnesium is burned in the
oxygen until no gas remains, what weight of magnesium
is required ?

210. What weight of sodium carbonate can be made
from 500 Kg. of common salt?

211. How much nitrogen tetroxide may be made
according to theory from 8 g. of lead nitrate?

212. How much iron could be obtained from 40 g. of
Fe2O3, and what weight of hydrogen would be required
to effect this process?

213. How much AgCl will be formed by the addition
of 10 g. of barium chloride to an excess of AgNO3?

214. How much red lead could be made from 800 Kg.

of litharge ?

215. What weight of A12O3 will be needed to prepare
94.8 g. of potash alum?

74 PROGRESSIVE PROBLEMS IN CHEMISTRY

216. How much CaSO4 can be formed from 37 g. of
CaCl2 ?

217. Calculate the amount of Ba(NO3)2 necessary to
precipitate 120 g. of dilute H2SO4 containing 50 % of
water.

218. How many Ib. of Ag2O are needed to make
3100 Ib. of oxygen ?

219. How much K2CO3 is needed to precipitate com-
pletely 109.5 g. of CaCl2?

220. What weight of phosphorus is needed to pro-
duce 100 g. of Mg2P2O7?

221. What weight of zinc, sodi-um, calcium, iron,
and magnesium will be required to produce 10 g. of
hydrogen ?

222. How many g. of CO2 will combine with 100 g.
of CaO to form CaCO3?

223. If 560 g. of bromine are treated with KOH,
what weight of potassium bromate is produced?

224. If 6 g. of carbon and 22 g. of oxygen are heated
in a closed tube, what is the weight of the resulting
substances ?

225. If 294 g. K2Cr2O7 are wanted, what weight of
K2CrO4 will be used?

226. If 5.75 g. of silver nitrate are added to 5.75 g.
of a solution of hydrochloric acid containing 10.22%
HC1, how much silver is precipitated and how much
remains in solution?

227. What weight of oxygen is needed to burn 15 g.
of charcoal (90 % C and 4% H)?

228. What weight of CO2 is needed to convert 90
tons of soda crystals into bicarbonate ?

WEIGHTS FROM EQUATIONS 75

229. What weight of chlorine could be obtained by
acting upon 20 g. of pure manganese dioxide with hy-
drochloric acid?

230. What weight of oxygen could be obtained by
the complete decomposition of 100 g. of pure potassium
chlorate ? If the chlorate used contained 10 % of its
weight of potassium chloride, what would be the differ-
ence in the amount of oxygen Obtained?

231. A solution of nitric acid of sp. gr. 1.46 contains
80 % of HNO3. What weight of this solution is theo-
retically required to dissolve 10 g. of copper oxide?

232. How much BaO2 would yield as much oxygen
as 250 g. of mercuric oxide?

233. When 0.542 g. of a salt of copper had been dis-
solved in water and precipitated by sodium hydrate,
the precipitate was dried and ignited, and it then
weighed 0.242 g. What was the percentage of copper
in the salt?

234. A mixture of 4 g. of sodium oxide and 6 g. of
sulphur trioxide will give what weight of sodium sul-
phate?

235. A manufacturer of bleaching powder requires
400 tons of chlorine. How much salt, manganese con-
taining 59 % of the dioxide, and sulphuric acid contain-
ing 58 °/0 of real acid will he need ?

236. What weight of potassium bromate can be ob-
tained by neutralizing 1520 g. of bromine with potash?

237. lodic acid may be obtained by passing a stream
of chlorine through water containing iodine in suspen-
sion. How much iodine and chlorine will be needed
to prepare 100 g. of iodic acid ?

76 PROGRESSIVE PROBLEMS IN CHEMISTRY

238. What weight of fluorspar would be required
to furnish sufficient hydrogen fluoride (by interaction
with sulphuric acid) to convert 5 g. of quartz into
silicon fluoride?

239. Calculate the weight of chlorine, at standard
conditions, necessary to give, by interaction with water,
an amount of oxygen that will just suffice for the oxida-
tion of 10 g. of mercury to mercuric oxide.

240. What weight of sulphuric acid can be prepared
from 100 g. of sulphur ?

241. Calculate the weight of potassium in a sample
of pure sylvite (KC1) which, on being analyzed, gave
2.230 g. of chlorine.

242. What weight of copper is present in a sample
of pure copper sulphate which, on being analyzed, gave
30.2 g. of sulphur trioxide, SO3?

243. Calculate the percentage purity of a sample of
horn silver which, on being analyzed, gave 74.2%
of silver.

244. When 8.2 g. of crystallized barium chloride
and 7 g. of sulphuric acid (70 % H2SO4) were brought
together in aqueous solution, what weight of barium
sulphate was precipitated ?

245. Compare the weights of aluminum and zinc
necessary for the production of equal weights of hydro-
gen by interaction with an acid.

246. Compare the weight of calcium nitride (Ca3N2)
(in its interaction with water) and the weight of ammo-
nium chloride (in its interaction with a base) necessary
to give the same weight of ammonia.

WEIGHTS FROM EQUATIONS 77

247. What relative weights of cupric oxide and cu-
prous oxide are procurable from the same weight of
copper?

248. If 2.4 g. of ammonia reduced 17 g. of hot cupric
oxide to copper, calculate the reaction quantity of
cupric oxide required per molecule of ammonia.

249. If 3 g. of silver nitrate and 1 g. of potassium
chloride were brought together in aqueous solution,
what weight of silver chloride would be precipitated ?

250. If 12 g. of an alloy of aluminum and zinc
(containing 33^ % of zinc) were placed in a vessel con-
taining 180 g. of hydrochloric acid (35 % HC1), what
volume of hydrogen, at standard conditions, would be
liberated ?

251. A specimen of silver containing 3% copper
weighed 9.8 g. After solution in nitric acid, an excess
of sodium chloride was added to it. Calculate the
weight of the silver chloride precipitated.

252. What weight of potassium hydroxide may be pre-
pared by the action of 100 g. of potassium upon water ?

253. What weight of potassium will be required in
the preparation of 20 g. of potassium carbonate ?

254. What weight of magnesium chloride may be
obtained by the action of hydrochloric acid upon 10 g.
of magnesium carbonate ? What weight of carbon
dioxide will be liberated ?

255. What weight of sulphur dioxide can be obtained
by the action of an acid upon 250 g. of sodium sulphite ?

256. If sodium nitrate, ammonium nitrate, and potas-
sium nitrate were the same price per lb., which would
be cheapest to use for preparing nitric acid, and why ?

78 PROGRESSIVE PROBLEMS IN CHEMISTRY

257. How much sulphuric acid and potassium nitrate
would be required in order to prepare 100 g. of nitric
acid?

258. What weight of chrome-alum may be obtained
from 20 g. of crystallized potassium sulphite and an
excess of chromium sulphate ?

259. What weight of ammonium-magnesium phos-
phate (NH4MgPO4, 6 H2O) could be formed from a solu-
tion containing 50 g. of crystallized magnesium sulphate
and an excess of ammonia and sodium phosphate?

260. What weight of iron-ammonium alum may be
formed when 12 g. of ammonium sulphate and 30 g.
of ferric sulphate are brought together in concentrated
aqueous solution ?

261. When 100 g. of mercury and 20 g. of sulphur
are rubbed together, what weight of mercuric sulphide
may be formed ?

262. A solution containing 5 g. of potassium iodide is
precipitated with silver nitrate. What will be the
weight of the precipitate of silver iodide ?

263. What quantities of nitre and Chili saltpeter,
respectively, will be required to obtain the maximum
quantity of nitric acid by reaction with 140 Kg. of 97 %
sulphuric acid ?

264. Calculate the weight of air required to burn 1
ton of coal possessing the following percentage com-
position: carbon, 88.42; hydrogen, 5.61 ; oxygen, 5.97.

265. How much marble and hydrochloric acid con-
taining 22 % HC1 are needed to yield 10 g. of carbon
dioxide ?

WEIGHTS FROM EQUATIONS 79

266. A piece of metallic iron immersed in a solution
of copper for a long time, in order to precipitate all the
copper, was found to have lost in weight 0.52 g.
What was the amount of copper in the solution ?

267. A solution of mercuric chloride contains 80 g.
of the salt per 1. ; sodium hydrate is added in excess to
175 cc. of the solution ; what will the precipitate weigh
if collected and dried ?

268. How many tons of oil of vitriol containing 70 %
H2SO4 are needed to convert 100 tons of salt into salt
cake ?

269. What increase in weight will occur on burning
10 g. of phosphorus in a tube through which oxygen is
passed, supposing that none of the product is lost ?

270. How many g. of iodine will be liberated from
an excess of a saturated solution of potassium iodide,
into which the gas evolved from heating 4.34 g. of
manganese dioxide with hydrochloric acid is passed ?

271. What weight of potassium dichromate must be
heated with hydrochloric acid in order to evolve suffi-
cient chlorine to liberate the iodine from 1.656 g. of
potassium iodide ?

CHAPTER VII

Volumes from Equations

1. What weight of 95 % alcohol is needed to yield
20 m.3 of ethylene at + 94° F. and 730 mm.?

2. A 1. of water is acted upon by phosphorus ' tri-
bromide; what will be the weight of the products and
the volumes of the gaseous ones at + 4° C. and 760
mm.?

3. A tank ^ m. long, | m. wide, and ^ m. deep is
filled with water and the water decomposed. What
volumes of hydrogen and of oxygen result, if measured
at -13° C. and 790 mm.?

4. If 130 1. of CO2 are passed through a KOH
solution, how many g. of KOH will be converted into
K2C03?

5. If 100 g. of Na2CO3 -are 'treated with HC1, how
many g. of salt and how many 1. of CO2 will be
formed ?

6. If 1 m.3 of CO2 is absorbed by Ca(OH)2, what
weight of CaCO3 will be formed?

7. An ore contains 67 A % of MnO2; what volume
of chlorine could be obtained by treating 300 tons of
this ore with HC1?

8. How much acetic acid must be decomposed in
order to obtain 100 1. of CH4?

80

VOLUMES FROM EQUATIONS 81

9. From 100 Ib. of pure limestone how many 1. of
CO2 can be obtained? What weight of lime?

10. 2 KNO3 -}- 3 C + S = 3 CO2 + N2 + K2S. In the
above equation find the weights and volumes of the
gases produced and the weight of carbon and sulphur
when 10 g. of KNO3 are used.

11. How much phosphorus can be burned in 4 1. of
" laughing gas " measured at + 14° C. ?

12. What weight of HBr will result if 1 m3. of
hydrogen is caused to unite with bromine vapor by
passing the mixture over a catalytic agent?

13. How many g. of zinc are necessary for the pro-
duction, by the action of muriatic acid, of 90 1. of
hydrogen measured under standard conditions?

14. If 19 g. of CS2 are burned, what are the weights
and volumes of the products ?

is. 3 Cu20 + 14 HN03 = 6 Cu(NO3)2 + 7 H2O +
2 NO. 100 g. of Cu2O are used. Find volume of the
gas produced.

16. What volume of nitrous oxide measured at 0° C.
and 750 mm. would be evolved by the decomposition of
10 g. of ammonium nitrate?

17. When 12 g. of carbon burn in the air, find
the volume of the resulting gas at 1 atmosphere and
0°C.

18. A balloon of 100,000 ft.3 capacity is to be filled
with hydrogen; how many Ib. of zinc and sulphuric
acid will be needed?

19. How much water can be decomposed by 20.7 g.
of sodium, and what volume of hydrogen would be set
free?

82 PROGRESSIVE PROBLEMS IN CHEMISTRY

20. What volume of hydrogen will unite with 24 g.
of oxygen to form water ? What volume of hydrogen
and of oxygen could be obtained by the electrolysis of
10 g. of water?

21. With what weight of hydrogen will 30 g. of
oxygen unite to form water?

22. With how much sulphuric acid must zinc be
treated in order to obtain 16,250 cc. of hydrogen ? Find
weight of ZnSO4.

23. If a tube containing copper oxide weighs before
hydrogen is passed through it 15.846 g., and after
the hydrogen has been passed 12.239 g., how many 1.
of hydrogen have united with the oxygen of the copper
oxide? How much water has been formed?

24. Find the number of 1. of gas given off by the
action of 130.8 g. of Zn on H2SO4.

25. Given 10 Kg. of iron to be acted upon by sulphuric
acid, what weight of acid is needed, and what is the
volume of hydrogen secured at — 6° C. and 780 mm.
pressure?

26. How many 1. of hydrogen at 0° C. and 760 mm.
pressure may be secured from 2000 g. of HC1 ?

27. What weight of NH4NO3 must be used to give
45 1. of N2O under standard conditions'?

28. How many 1. of hydrogen, under standard condi-
tions, will result from the electrolysis of 18 g. of water?

29. How many g. of sulphur must be burned to yield
100 1. of sulphur dioxide under standard conditions?

30. What would be the volume, under standard con-
ditions, of the hydrogen liberated in the decomposition
of 30 g. of water by means of sodium ?

VOLUMES FROM EQUATIONS 83

31. What volume of hydrochloric acid, under stand-
ard conditions, can be obtained by the action of sul-
phuric acid upon 150 g. of salt?

32. What volume of chlorine, measured under stand-
ard conditions, will convert JjO g. of potassium hydroxide
into chloride and chlorate according to the reaction :

6 KOH + 3 C12 = 5 KC1 + KC1O3 + 3 H2O?

33. How many cc. of marble, CaCO3 (sp. gr. 2.70),
must be dissolved in HC1 to give 5 1. of CO2?

34. How many g. of air, approximately, ought it to
take to burn 10 1. of gaseous C3Hg, if ^ of the volume
of the air is oxygen?

35. (a) How many Kg. of CO2 will form in the com-
bustion of a cylindrical tank of liquid acetylene, C2H2,
which is 15 cm. in diameter and 18 dm. high, if its
sp. gr. is 0.8? (5) If the CO2 is absorbed by lime
water, how many Kg. of CaCO3 would form? (<?) How
many days will this tank of C2H2 serve to light a house
with 6 gas jets, each running 5 hours and burning J ft.3
per hour, if 1 ft.3 equals 27,000 cc.?

36. What volume of sulphur dioxide would result
from heating in the air 1 ton of pure iron pyrites, assum-
ing that all of the sulphur in the pyrites is converted
into sulphur dioxide ?

37. What volume of hydrogen sulphide will be
formed upon treating 40 g. of ferrous sulphide, FeS,
with hydrochloric acid?

38. What volume and what weight of sulphur di-
oxide will be formed upon burning 1 1. of hydrogen
sulphide ?

84 PROGRESSIVE PROBLEMS IN CHEMISTRY

39. Under a barometric pressure of 740 mm. at + 20°
C., what weight of ammonium nitrate must be decom-
posed to generate sufficient nitrous oxide to fill a balloon
holding 200 1. ?

40. What weight of carbon will be required to com-
pletely convert into carbon dioxide 20 1. of oxygen
measured under a pressure of 780 mm. of mercury at
+ 30° C. ? What volume of carbon dioxide, under the
same conditions, will be formed ?

41. Excess of carbon is thrown into 100 g. of fused
KNO3. What volume of nitrogen and of CO2 is
evolved ?

4 KNO3 + 50 = 2 K2CO3 + 2 N2 + 3 CO2.

42. Find the number of 1. of water needed to slake a
bin of lime containing 1376 Kg.

43. It is desired to fill with oxygen at + 35° C. and
530 mm. a gas-holder, the capacity of which is 45 1. ;
what weight of KC1O3 is requisite?

44. A Kg. of KC1O3 will yield what weight of
oxygen ; what volume at + 24° C. and 736 mm. ?

45. If 256 g. of sodium peroxide are decomposed by
water, what is the volume of the oxygen secured at
+ 21° C. and 710 mm. ; at - 80° C. and 1410 mm. ?

46. What volume of hydrogen may be secured from
12 Kg. of water, with the aid of potassium, the hydrogen
to be measured at + 25° C. and 780 mm. ?

47. What weights of water and of potassium are
needed to generate 8 1. of hydrogen at + 25° C. and
760mm.?

48. How many 1. of hydrogen at + 22° C. and
714 mm. will 98 g. of hydrochloric acid yield ?

VOLUMES FROM EQUATIONS 85

49. How much zinc is needed to prepare 100 1. of
hydrogen at 0° C. and 740 mm. ?

50. Am.3 gas-holder is to be* filled with oxygen at
+ 100° C. and 721 mm. What weight of Pb(NO3)2
is needed to prepare it?

51. If 10 1. of hydrogen at + 15° C. are burned, what
volume of steam at + 300° C. is formed?

52. How many 1. of chlorine can be obtained by
treating 50 g. of manganese dioxide with hydrochloric
acid?

53. What volume of arsine will result when 150 mg.
arsenic trioxide is acted upon by nascent hydrogen?

54. How much lead sulphide can be precipitated by
17 1. of hydrogen sulphide ?

55. What volume of sulphur vapor would result from
the decomposition of a 1. of H2S at + 500° C. if the
density of S is 96 and its atomic weight is 32 ?

56. What volume of zinc vapor will unite with
300 cc. of oxygen to form zinc oxide? Zn has vapor
density of 32.5; atomic weight 65.

57. How much phosphoric fluoride by volume can
be obtained from 100 g. of phosphorus pentachloride ?

5 AsF3 + 3 PC15 = 5 AsCI3 + 3 PF5.

Supposing all the products to be gases, find the vol-
umes.

58. How many cc. of solid arsenic (sp. gr. 5.73) could
be obtained from 1250 cc. of arsine at a temperature of
+ 105°C.?

59. If 425 1. and 328 cc. of oxygen at + 24° C. and
658 mm. are wanted, what weight of BaO2 is needed
to make that amount ?

86 PROGRESSIVE PROBLEMS IN CHEMISTRY

60. If 752 1. of oxygen at + 19° C. and 729 mm. are
wanted, what weight of water must be decomposed to
secure that amount, and what volume of hydrogen is
obtained at the same time ?

61. Three 1. of water are to be decomposed. What
volumes of hydrogen and oxygen result at — 21° C. and
790 mm. ?

62. The hydrogen secured from 100 Ib. of sulphuric
acid is burned. What weight of water results ?

63. The hydrogen derived from 2 1. of water is
burned. What is the weight of the product?

64. The hydrogen derivable from 98 Kg. of pure sul-
phuric acid is to be burned ; what is the weight of the
product? What is its volume at + 4° C. and 760 mm. ;
at + 150° C. and 754 mm. ?

65. How much ammonium nitrate is needed to pre-
pare 100 1. of nitrous oxide at — 5° C. and 600 mm. ?

66. How much copper is needed to prepare 100 1. of
nitric oxide at - 100° C. and 760 mm. ?

67. What weight of phosphorus, if all is converted,
is necessary to produce 100 1. of phosphine at + 68° F.
and 720 mm. ?

68. What volumes of hydrogen and oxygen, respec-
tively, result from the decomposition of 100 1. of water
vapor at + 200° C. ?

69. What weight of carbon is necessary to reduce. 20
g. of carbon dioxide to carbon monoxide ? How many
1. of air at + 22° C. and 760 mm. are required to burn
the monoxide thus formed to the dioxide ?

VOLUMES FROM EQUATIONS 87

70. What volume of oxygen, measured under stand-
ard conditions, will be evolved when 108 g. of mercuric
oxide are decomposed by heating ?

71. If 15 Kg. of H2SO4 are worked up by the aid of
copper into sulphur dioxide, what weight of Cu is
needed, and what weights and volumes of the products
result at + 35° C. and 730 mm. ?

72. A 1. of chlorine measured at + 25° C. and 753
mm. is used to expel the iodine from potassium iodine.
What weight of iodine is expelled ?

73. Find, under standard conditions, the volume of the
gases resulting from the electrolysis of 72 g. of water.

74. If 50 gal. of carbon monoxide are burned, what
volume of oxygen at + 48° C. and 675 mm. is necessary,
and what volume of carbon dioxide is secured ?

75. One hundred g. of chlorine are to be united with
hydrogen. What volume of hydrogen is needed at
4- 150° C. and 735 mm., and what volume of hydro-
chloric acid gas results ?

76. The hydrogen sulphide secured from 55 Kg. of
ferrous sulphide is decomposed. What volume of hydro-
gen results at 0° C. and 760 mm. ; at + 75° C. and 780
mm.?

77. If 1500 g. of HC1 are decomposed, what volumes
of H and of Cl are secured at + 28° C. and 790 mm. ?

78. The HC1 securable from 550 g. of common salt is
decomposed. What volumes of H and Cl result at

-20°C. and 778 mm.?

79. The water resulting from the combustion of 1 g.
of hydrogen is decomposed. What are the volumes of
H and O at + 4236 C. and 787 mm. ?

88 PROGRESSIVE PROBLEMS IN CHEMISTRY

80. What weight of material is required to secure
500 1. of ammonia at 0° C. and 700 mm. ?

81. If 500 g. of oxalic acid are decomposed with sul-
phuric acid, what volumes of carbon monoxide and
dioxide result if measured at — 21° F. and 640 mm. are
obtained ?

82. How much ferrous sulphide is needed to pre-
pare 100 1. of hydrogen sulphide at - 10° C. and 800
mm. ?

83. If 13,720 cc. of hydrogen chloride at - 10° C.
and 730 mm. are decomposed by electricity, what are
the volumes and weights of the products ?

84. What weight of calcium carbide must be em-
ployed if we wish to fill with acetylene gas a reservoir,
12 m. by 10 m. by 60 cm., at + 28° C. and 760 mm. ?

85. What volume of nitrous oxide, measured at 0° C.
and 780 mm., may be obtained from 10 Kg. of ammonium
nitrate ?

86. How many 1. of chlorine at -}- 21° C. and 750 mm.
are needed to manufacture 10 Kg. of potassium chlorate,
provided there is no loss ?

87. What weight of calcium carbide must be em-
ployed to fill with acetylene gas a gas-holder that con-
tains 10,000 m.3 at + 18° C. and 750 mm. ?

88. The hydrogen chloride secured from 210 Kg. of
sodium chloride is employed for preparing hydrogen.
What is the volume procurable at +1200°C. and 2.5
atmospheric pressure ?

89. What volume of hydrogen at -f 40° C. and 715
mm. will 1 Kg. of sodium liberate from water?

VOLUMES FROM EQUATIONS 89

90. What volume of arsine at +20° C. and 760 mm.
results from the action of nascent hydrogen upon 10 g.
of arsenious oxide ?

91. What volume of hydrogen sulphide at + 110° C.
and 660 mm. may be made from 210 Kg. of ferrous sul-
phide ?

92. What volume of NH3 may be obtained from 430 g.
of NH4C1?

93. What volume of oxygen is needed at 0°C. and
760 mm. to burn completely 42 1. of hydrogen sulphide
measured at + 20° C. and 780 mm.?

94. A container measuring 50 cm. by 9 dm. by 300
mm. is filled with HC1 gas at + 20° C. and 740 mm.
A precisely similar measure of ammonia is introduced ;
what weight of ammonium chloride is formed ? What
is left over and how much ?

95. What volume of gaseous products, measured at
4- 150° C. and 760 mm., is secured by the decomposition
by heat of 2 Kg. of ammonium nitrate ?

96. One Kg. of phosphorous acid is to be made by
acting upon phosphorus tribromide with water. What
weight of the tribromide is needed, and what volume of
hydrogen bromide is produced ?

97. If 1300 1. of hydrogen sulphide at +88°C. and
742 mm. are decomposed, what weight of sulphur re-
sults? What is the volume of the resultant sulphur
measured at +1450° C. and 760 mm.?

98. What volumes of hydrogen and nitrogen, meas-
ured at — 10° C. and 730 mm., result if we decompose
by electricity all of the ammonia that may be secured
from 1000 g. of ammonium sulphate ?

90 PROGRESSIVE PROBLEMS IN CHEMISTRY

99. Given 20 1. of sulphur vapor at + 500° C., what
quantity, by weight, of sulphur trioxide can be made
from it ?

100. To secure 100 Kg. of H2S at - 10° C. and 750
mm., what weight of Na2S and of hydrochloric acid is
needed ? And what other products are secured?

101. How many g. of sulphur are needed to produce
110 1. of sulphur dioxide at + 360° F. and 739 mm.?

102. If 10,000 m.3 of hydrogen sulphide at two at-
mospheres pressure and + 10° C. are wanted, what
weight of materials is needed to make it ?

103. What volume of hydrogen chloride is formed
when 10 1. of chlorine combine with hydrogen ?

104. What volume of nitric oxide, measured at 743
mm. and + 18° C., will be produced by treating 18 g.
of metallic copper with an excess of nitric acid ?

105. How many 1. of oxygen are required to burn
3 1. of AsH3, and what will be the weight of each of
the products ?

106. What volume of carbon dioxide, measured at
750 mm. pressure and +20°C., will be formed when
17 g. of a candle, 85 % C and 15 % H, is burned ?

107. A steel cylinder of 4 ft.3 capacity is to be
filled with carbon dioxide under a pressure of 150 Ib.
to the in.2. What weight of marble and hydrochloric
acid would be needed to produce the necessary amount
of gas ?

108. How many 1. of acetylene can be obtained from
50 g. of calcium carbide that is 93 % pure, if the gas is
evolved at a temperature of + 40° C. and a pressure
of 1 J atmospheres ?

VOLUMES FROM EQUATIONS 91

109. What volume of sulphur dioxide at + 20° C.
and 740 mm. can be obtained by the action of 20 g.
of sulphuric acid upon copper ?

110. How many 1. of carbon dioxide would result
from burning 5.384 g. of carbon?

111. What volume of oxygen will be required to
burn 1 Kg. of carbon ?

112. What volume of air, of 21 % oxygen by volume,
is needed to burn completely 1 ton of anthracite coal,
assumed to be pure carbon ?

113. How many 1. of chlorine can be obtained from
34 g. of salt ?

114. What volume of oxygen, measured at + 15° C.
and 772 mm. pressure, can be obtained from 100 cc. of
sulphuric acid (sp. gr. 1.84)?

2 K2Cr207 + 8 H2S04 = 2 K2SO4 + 2 Cr2(SO4)3

+ 8 H20 + 3 02.

115. How many 1. of air will be required to burn
5 g. of phosphorus?

116. If 10 1. of hydrofluoric acid gas were made from
CaF2 and H2SO4, how much CaSO4 was made at the
same time?

117. What volume of nitrous oxide, measured at
0° C. and 750 mm., would be evolved by the decomposi-
tion of 10 g. of ammonium nitrate ?

118. What volume of carbon dioxide, under standard
conditions, can be obtained from exactly 10 g. of
calcium carbonate?

119. If 12 g. of carbon are burned to carbon dioxide,
what will be the volume of the gas compared with 1 g.
of hydrogen at the same temperature and pressure ?

92 PROGRESSIVE PROBLEMS IN CHEMISTRY

120. From 2078 g. of sodium chloride what volume
of chlorine can be obtained ?

121. If 9.6 g. of sulphur are heated in hydrogen,
what volume of hydrogen sulphide is formed ?

122. What volume of hydrogen, under normal condi-
tions of temperature and pressure, can be obtained from
10 £. of pure zinc ?

123. Calculate the number of g. of ferrous carbonate
required to react with sulphuric acid in order to set
free 60 1. of carbon dioxide.

124. If 40 g. of Ca react with water, what is the
weight and volume of hydrogen?

125. If 600 g. of MnO2 are decomposed by heat,
what is the volume of O at + 13° C. and 781 mm. ?

126. If 55.8 1. of hydrogen at 0° C. and 760 mm.
are required, how much zinc and KOH are needed
for its formation ?

127. If 168 g. of MgCO3 are heated and the CO2
is passed into KOH solution, what weight of K2CO3
will be formed ?

128. If 147 g. K2Cr2O7 are heated with H2SO4, what
will be the volume and weight of gas evolved ?

129. How much alcohol should be burned to give
13 1. of steam ?

130. If 1000 cc. of H2S burn in the air, find (a)
weight and volume of oxygen used, and (b) products
formed.

131. If 16 1. of SO2 are produced by burning a piece
of sulphur, how heavy was the sulphur ?

132. What volume of chlorine is required to unite
with 71 g. of gold to produce auric chloride ?

VOLUMES FROM EQUATIONS 93

133. How many 1. of oxygen at 0° C. and 760 mm.
could be obtained from a pailful of water, the water
weighing 12 Kg. ?

134. How much salt is necessary to produce 480 g.
of chlorine, and how much space would be filled by that
amount of chlorine at + 20° C. and 755 mm. pressure ?

135. The sp. gr. of acetylene is 0.92. What volume
would be occupied, at + 20° C. and 750 mm., by the
gas generated from 480 g. of calcium carbide, 95 %
pure?

136. What weight of potassium chlorate is necessary
to yield 6 1. of oxygen measured over water at
+ 18.1° C. and 759.9 mm.?

137. If 2 g. of steam are passed over red-hot iron,
what volume of hydrogen at + 10° C. and 770 mm. is
formed ?

4 H20 + 3 Fe = Fe3O4 + 4 H2.

138. What weight of sodium would be necessary to
liberate 75 cc. of hydrogen at 0° C. and 760 mm. by
reacting with water ?

139. What volume of oxygen at 0° C. and 760 mm.
would be liberated by heating 1.05 g. of mercuric
oxide ?

140. What volume of hydrogen, measured over water
at + 17.3° C. and 758.2 mm., will be generated by the
reaction of 20 g. of zinc with dilute sulphuric acid ?

141. What volume of "laughing gas," measured at
4- 20° C. and 750 mm., may be made from 12 g. of
ammonium nitrate ?

142. How much phosphorus is required to remove
the oxygen from a 1. of air ?

94 PROGRESSIVE PROBLEMS IN CHEMISTRY

143. How much alcohol will be needed to use up
during combustion 116 g. of oxygen ?

144. Find the volume of oxygen needed to burn com-
pletely 20 g. of alcohol and the volumes of the products.

145. What volume of phosphine is evolved during
the solution of 62 g. of phosphorus in Ba(OH)2 solu-
tion ?

146. Calculate the volume of ammonia obtainable
from 126 g. of HNO3.

147. If 5580 cc. of HF are passed over heated so-
dium, how much of each product is obtained?

148. An excess of Ag2O is thrown into 136 g. of a
solution of H2O2 containing 75 % water ; what gas is
evolved, and what will be its volume at — 133° C. and
1520 mm. ?

149. If 55 g. of HgO are heated, what is the volume
of the oxygen at 667 mm. and + 22° C. ?

150. To produce 112 1. of hydrogen from steam, how
much charcoal must be used?

151. MnO2 is treated with 10 1. of HC1. Find
weight and volume of chlorine produced.

152. What weight of ammonium sulphate would be
produced by neutralizing 100 g. of pure sulphuric acid
with ammonia?

153. How much carbon dioxide by weight and by
volume can be prepared from 275 g. of calcium carbon-
ate?

154. What volume of chlorine at + 15° C. must be
passed over 20 g. of AgNO3 to obtain N2O5?

C12 + 2 AgN03 = 2 AgCl + 0 + N2O5.

VOLUMES FROM EQUATIONS 95

155. What volume of H2S would be needed to pro-
duce 10 g. of CuS from a CuSO4 solution?

156. Calculate the volume of carbon dioxide, meas-
ured at 0° C. and 760 mm., that can be made from 50 g.
of calcium carbonate and an excess of hydrochloric acid.

157. Into what volume of oxygen will 96 g. of ozone
break up?

158. If 500 g. of hydrogen are needed, how much
steam is required?

159. If 5 g. of zinc are dissolved in acid, how many
cc. of hydrogen are freed when measured at + 10° C.
and 750 mm. ?

160. How many cc. of HC1 solution, containing
240 g. of HC1 per 1., will be required to decompose
2500 g. of CaCO3?

161. How many 1. of (a) hydrogen and (5) carbon
monoxide, at + 10° C. and 750 mm., can be obtained
by passing steam over 24 g. red-hot charcoal ?

162. If 13 g. of sodium are placed on water, the con-
ditions being + 11° C. and 700 mm., how many m.3 of
gas are liberated?

163. If 2 g. of potassium are heated in NH3, how
much potassium amide and what volume of hydrogen
at +15° C. are formed?

K + NH8 = KH2N + H.

164. What weight of nitric oxide would be needed
to unite with the oxygen of the air in a 10 1. flask?

165. If a man exhale one m.3 of CO2 in an hour, at
+ 16° C., how long will it take him to produce 5 Kg.
of the gas?

96 PROGRESSIVE PROBLEMS IN CHEMISTRY

166. When 10 g. of sulphur burn in contact with
hydrogen, what volume and weight of H2S could be
produced?

167. If 2 1. of nitrosyl chloride at -f- 15° C. are passed
over warm lunar caustic, how much N2O5 is formed?

NO2C1 + AgNO3 = AgCl + N2O5.

168. A balloon holds 15,000 1. What weight of
NH4NO3 will give enough gas to fill the balloon at
+ 20° C. and 600 mm. ?

169. Find weight of copper needed to produce 15 1.
of NO at 871 mm. and + 22° C.

170. If 20 1. of oxygen under 420 mm. pressure will
be enough to burn completely 20 g. of phosphorus, at
what temperature is it?

171. If 300 cc. of NH3 react with chlorine, what volume
of nitrogen is obtained at —6° C. and 327 mm. pressure?

172. What volume of hydrogen is required by 19 g.
of chlorine to produce hydrochloric acid ?

173. If 300 cc. of chlorine are obtained from the elec-
trolysis of HC1, what weight and volume of hydrogen
are given off, and what weight of HC1 is used?

174. If 130 g. of pyrolusite (90.7 % pure) are heated
with an excess of HC1, what is the volume of the gas
given off?

175. A tank contains 6m.3. How many g. of zinc
and acid are needed to fill it with hydrogen at standard
conditions?

176. If 1 g. each of K, Li, Na, and Ca are placed in
water separately and the hydrogen of each is measured,
which metal will give the greatest yield in cc. ? Find
weight from each.

VOLUMES FROM AQUATIONS 97

177. Find weight of 171. of ethylene. What volume
of oxygen would be needed to burn it ?

178. How many g. and 1. of oxygen will be given by
300 g. of K2Cr2O7 + H2SO4 in excess ?

179. How many 1. of chlorine will be liberated by
treating 39 g. of KC1O3 with sufficient HC1 solution to
decompose it?

180. If 98 g. of H2SO4 react on K2Cr2O7, what
volume of oxygen, measured at + 12° C. and T99 mm.,
will be evolved ?

181. Calculate the weight of NH4NO3 required to
produce 1900 cc. of N2O, measured at + 12° C. and 710
mm.

182. If 500 g. of marble are treated with HC1, how
many g. of HC1 are needed, and what will be the
volume of the resulting gas at + 15° C. and 740
mm.?

183. How many 1. of muriatic acid will be liberated
by treating 585 g. of salt with H2SO4?

184. The iodine in 100 volumes of HI is liberated in
succession by chlorine and oxygen. Find the volume
of chlorine and of oxygen used.

185. How much SnCl2 must be electrolyzed to give
chlorine enough to convert 180 g. of antimony into
SbCl3?

186. When 100 g. of NH4NO3 are decomposed, find
the volume of N2O measured at -f 1° C. and 800 mm.

187. If 50 g. of CO are needed, what volume of CO2
should be passed over red-hot coke ?

188. What volume of H2S, measured at —31° C. and
777 mm., can be obtained from 10 g. of FeS?

98 PROGRESSIVE PROBLEMS IN CHEMISTRY

189. What volume of chlorine at +27° C. and 777
mm. will be required to convert 232 g. of Bi2O3 into
Bi208?

190. What volume of NH3 will 50 g. of lime liberate
from an ammonia salt?

191. What volumes and weights of hydrogen and
oxygen are contained in 13 1. of water?

192. If 10 g. of graphite burn in oxygen, what is the
weight and volume of CO2 formed?

193. What weight of salt will yield (a) 17 1. chlo-
rine; (6) 13 g. Na2SO4; (c) 30 g. MnSO4; (d) 3 1. of
water ?

194. If 30 cc. of air and 60 cc. of hydrogen are ex-
ploded, what is the volume and weight of the residue ?

195. If 16 g. of HgO are heated, what is the weight
of residue; the weight and volume of gas given off?

196. If 100 g. of steam are passed over red-hot iron,
what volume of hydrogen at +10° C. and 742 mm. is
formed ?

197. What volume of oxygen can be obtained from
20 g. of manganese dioxide by heating it alone?

198. What volume of oxygen at +10° C. and 743
mm. can be obtained by the decomposition of a 1. of
sulphuric acid possessing a density of 1.84 at 0° C.?

199. What weight of hydrochloric acid is produced
in the manufacture of 100 tons of salt cake? What
volume of gas escapes, supposing the manufacturer to
condense only 92 % of the quantity evolved?

200. What volume of oxygen at 0° C. and 760 mm.
can be theoretically obtained from 1 Ib. of bleaching
powder ?

VOLUMES FROM EQUATIONS 99

201. If 1 g. of phosphorus is to be converted into
the pentachloride, how many 1. of chlorine are re-
quired?

202. How much marble and hydrochloric acid con-
taining 22 % HC1 are needed to yield 10 1. of carbon
dioxide at + 15° C. and 760 mm. barometric pressure?

203. Calculate the volume of nitrogen monoxide at
+ 15° C. and 740 mm. produced on heating 30 g. of
ammonium nitrate.

204. I require 10 1. of carbon monoxide at 0° C. and
760° mm. pressure. How many g. of (a) oxalic acid;
(6) of formic acid ; and (c) of potassium ferrocyanide
shall I need ?

205. A gas bag has a capacity of 45 1. ; how much
manganese dioxide containing 70 % of MnO2 is required
to fill it with oxygen at 4-15° C. and 760 mm.?

206. How many cc. of oxygen and hydrogen, measured
at +12° C. and under a pressure of 762 mm., can be
obtained by the electrolysis of 10 g. of water?

207. What weight of ammonia and of chlorine is
needed to produce a 1. of nitrogen ?

208. If 100 g. of steam are passed over 1000 g. of
red-hot iron wire, what volume of hydrogen is evolved,
measured at + 10° C. and 742 mm., and what weight of
iron oxide is produced ?

209. Find weight of hydrogen needed to unite with
21 g. of oxygen to form water. How much with (a)
20ff.;(i)76g.;O)300g.?

210. How many g. of mercury and how many 1. of
chlorine, measured at a temperature of -f- 16° C. when
the barometer stands at 770 mm., are consumed in the
manufacture of 100 g. of corrosive sublimate?

100 PROGRESSIVE PROBLEMS IN CHEMISTRY

211. Find the volume of HF from 71 g. of CaF2 and
enough H2SO4.

212. What weight of NH4OH is needed to produce
131 i. of NH3?

213. How many g. of CaCO3 will produce 114 1. of
C02?

214. How much sodium acetate and caustic soda is
needed to yield 300 cc. of CH4?

215. If 8 g. of methyl alcohol burn in air, what vol-
ume of oxygen is used, and what are the weights of the
products ?

216. What weight and volume of chlorine is produced
by treating 300 g. of HC1 with enough HNO3?

217. How many g. of acid calcium carbonate will
200 1. of CO2 with water produce from CaCO3?

218. What volume of nitrogen, measured at — 1° C.
and 800 mm., is given off on heating 84 g. ammonium
dichromate ?

219. When 2 g. of sulphur are burned in a closed
vessel containing 16 1. of air (21 % O), what volumes
of oxygen and sulphur dioxide are present after com-
bustion ?

220. How much calcium will liberate 56 1. of hydro-
gen from water?

221. When 83 g. of cobaltic oxide are heated with
HC1, what volume of chlorine is evolved?

222. A balloon holds 200 Kg. of hydrogen. How
much Zn and HC1 are needed? Find volume of hydro-
gen at + 90° C. and 760 mm.

223. A room is 6 m. x 760 cm. x 896 mm. Find the
weight of air in the room.

VOLUMES FROM EQUATIONS 101

224. A room 30 m. x 18 m. x 15 m. is filled with
oxygen. What weight of gas does it contain ?

225. What volume at + 20° C. and under a pressure
of two atmospheres will 100 1. of sulphur dioxide, meas-
ured at 0° C. and under a pressure of one atmosphere,
occupy? What weight of sulphur is necessary to pro-
duce this amount of sulphur dioxide?

226. When 10 g. of turpentine are burned, what
volume of carbon dioxide is formed?

227. How many 1. of hydrogen are obtained on dis-
solving 16 g. of magnesium in dilute sulphuric acid ?

228. How many 1. of hydrochloric acid can be made
by the use of 575 g. of KC1?

229. When 1 g. of HgO and 1 g. KC1O3 and 1 g.
Pb(NO3)2 are each heated separately and the oxygen is
measured, calculate the weight and volume in each case.

230. How much ozone will 13 g. of oxygen make?
What residue and how much will there be ?

231. How much carborundum will 2 tons of sand
make ? What volume of CO will be produced ? (SiO2 +
3 C = SiC + 2CO).

232. Find the volume of HF which may be produced
from 300 g. of CaF2 at - 6° C. and 791 mm.

233. If 10 1. of carbon monoxide at + 14° C. and
760 mm. are required, what volume o*f carbon dioxide
must be passed over red-hot carbon, and what mass of
carbon is used?

234. How many 1. of hydrogen phosphide can be
made by the use of 250 g. of calcium phosphide?

235. How many 1. of hydrogen arsenide can be made
with 640 g. of zinc arsenide?

102 PROGRESSIVE PROBLEMS IN CHEMISTRY

236. How many 1. of hydrogen and of oxygen are
necessary to produce 10 cc. of liquid water?

237. How many g. of chalk are required to yield
15 1. of choke damp?

238. How many cc. of chlorine at a temperature of
+ 15° C. and under a pressure of 770 mm. can be ob-
tained from 150 g. of silver chloride?

239. How much cryolite is needed to prepare 100 1.
of hydrogen fluoride at + 100° C. and 500 mm.?

240. When 250 cc. of carbon dioxide are passed over
red-hot carbon, what volume of carbon monoxide will
be formed?

241. A room is 25 m. long, 15 m. broad, and 10 m.
high ; how much carbon dioxide will it contain at the
rate of 4 volumes in 10,000?

242. What weight in g. of sodium acetate is required
to yield 10 1. of methane at + 20° C. and 760 mm. ?

243. A piece of charcoal is burned in 2 J 1. of oxygen ;
how many 1. of carbon dioxide will be formed, and how
much will the carbon dioxide weigh?

244. If I wish to obtain 1 1. of oxygen by heating
mercuric oxide, what weight of the oxide shall I need?

245. What volume of chlorine would exactly decom-
pose 25 g. of hydriodic acid ?

246. What weight of copper and sulphuric acid is
needed to yield 3 1. of SO2?

247. What is the weight of 25 1. of carbon dioxide,
and what weight of pure baking soda would be required
to prepare it?

248. Phosphorus is burned in 15 1. of nitrous oxide ;
how many 1. of nitrogen will remain?

VOLUMES FROM EQUATIONS 103

249. What volume of hydrogen, measured over water
at + 18° C. and 746.4 mm., will be liberated by the
action of aluminum upon 20 g. of sulphuric acid con-
taining 41.5 % H2SO4?

250. An unknown volume of hydrogen sulphide re-
quired 110.34 cc. of chlorine for complete decomposi-
tion. What was the volume of the hydrogen sulphide?

251. What volume of hydrobromic acid at + 15° C.
and 770 mm. pressure would be produced by the action
of water upon 50 g. of phosphorus tribromide ?

252. What volume of oxygen would be required for
the complete combustion of 120 g. of bisulphide of
carbon?

253. What volume of oxygen would be required for
the combustion of 125 g. of boron?

254. If 20 g. of a silicate containing 20% of
silica are heated with fluorspar and strong sulphuric
acid, what volume of silicon fluoride will be produced ?

255. What weight of materials would be required to
prepare 10 1. of chlorine?

256. How much copper and nitric acid would be re-
quired in order to prepare 100 1. of nitric oxide ?

257. What volume of oxygen at + 120° C. and
743 mm. can be obtained by treating an excess of
+ KMnO4 with a 1. of sulphuric acid possessing a density
of 1.84 at 0°C.?

258. If 3.5 1. of gaseous hydrofluoric acid at + 10° C.
and 765 mm. were obtained by heating fluorspar with
oil of vitriol, what weight of fluorspar was used?

259. What volume of oxygen would be required to con-
vert 201 g. of phosphorus into (a) P2O3 and (6) P2O5?

104 PROGRESSIVE PROBLEMS IN CHEMISTRY

260. If 150 g. of iodine are heated with red phos-
phorus and water, what volume of hydriodic acid will
be produced?

261. What volume of sulphuretted hydrogen is re-
quired for the complete precipitation of a solution
containing 5 g. of As2O3?

262. If 20 g. of nitrogen are carried through the
following series of reactions, calculate the resulting
volume of nitrous oxide at standard conditions :

3Mg4-N2 =
Mg3N2 + 6 H20 = 3 Mg(OH)2 + 2 NH3

NH4N03 = N20 + 2 H20.

263. What weight and what volume of hydrogen
will be evolved by the action of 15 g. of sodium on
water ? What weight of sodium hydrate will be pro-
duced?

264. What volume of sulphuretted hydrogen at
+ 13° C. and 700 mm. would be produced by boiling
15 g. of antimony sulphide with strong hydrochloric
acid?

265. A piece of pure carbon weighing 12.5 g. is
lighted and plunged into a jar containing 16 g. of
oxygen ; how much carbon, if any, will remain un-
burned ?

266. What volume of hydrogen at — 5° C. and 770
mm. pressure would be evolved by dissolving 15 g.
of pure magnesium in hydrochloric acid?

267. Calculate the volume of carbon dioxide at
+ 22° C. and 740 mm. that will be liberated by the
action of acid upon 200 g. of calcium carbonate.

VOLUMES FROM EQUATIONS 105

268. What weight of magnesium will be required
for the liberation of 500 cc. of hydrogen at + 20° C.
and 740 mm. when acted upon by an acid?

269. What weight of aluminum will be required for
the liberation of 1420 cc. of hydrogen, measured over
water at + 18° C. and 746.4 mm., when acted upon by
HC1?

270. Calculate the relative weights of sodium chlo-
rate and potassium chlorate necessary to give 20 1. of
oxygen at — 4° C. and 770 mm.

271. Calculate the relative weights of potassium
chlorate and perchlorate (KC1O4) necessary to give
320 1. of oxygen at + 81° C. and 692 mm.

272. What volume of chlorine, measured at -f- 12° C.
and 750 mm. pressure, would be produced by heating
50 g. of common salt with sulphuric acid and manga-
nese dioxide ?

273. The iodine in 600 volumes of hydriodic acid is
liberated in succession by chlorine and by oxygen.
How many volumes of chlorine and how many volumes
of oxygen are required ?

274. A piece of sodium was completely converted
into a chloride by the absorption of 200 cc. of chlorine.
What was the weight of the sodium ?

275. How many 1. of sulphuretted hydrogen could
be obtained by the action of sulphuric acid upon 329 g.
of ferrous sulphide, and what volume of hydrogen
would it contain ?

276. How many 1. of oxygen would be required
in order to burn completely 53 1. of sulphuretted
hydrogen ?

106 PROGRESSIVE PROBLEMS IN CHEMISTRY

277. How many 1. of sulphur dioxide would be pro-
duced by burning sulphur in 158 1. of oxygen?

278. What weight and what volume of sulphur
dioxide ought to be obtained by heating 250 g. of
copper with sulphuric acid ?

279. If 60 g. of mercuric oxide are heated, what
volume of oxygen at -f- 91° C. and 380 mm. is given
off?

280. What weight of iron would be required to
expel 5 1. of hydrogen from hydrochloric acid ?

281. A gas tank will hold 321 g. of oxygen. What
weight and volume of nitrogen and of carbon dioxide
will it hold ?

CHAPTER VIII

Problems in the Combining Volumes of Gases
(Gay-Lussac's Law)

1. If 27 g. of ethylene are completely burned, what
is the volume of the products of combustion ?

2. If 20 1. of hydrogen and 10 1. of chlorine are exposed
to sunlight, what are the volumes of the resulting gases?

3. One 1. of marsh gas is burned. Find weight and
volumes of oxygen needed, and of gases produced.

4. If 100 cc. of dry ammonia gas are decomposed
by electricity, what are the weights and volumes of
gases formed ?

5. When 16 g. of CH4 burn in air, what is the
volume of CO2 produced and weight of water ?

6. If an electric spark is passed through each of the
following gaseous mixtures, calculate what volumes
result in each case :

1st mixture! ? volumes oxygen
i 1 volume hydrogen

0 -I . , f 2 volumes hydrogen
2d mixture 1 J

1 volume

0 -, . . f 1 volume hydrogen
3d mixture { %

I 2 volumes chlorine

A ,, . . f 1 volume oxygen
4th mixture \ * /.c .

2 volumes chlorine

107

108 PROGRESSIVE PROBLEMS IN CHEMISTRY

7. If 1 volume of carbon monoxide is mixed with
1 volume of oxygen and the mixture is exploded in a
closed place, what will be the volume of the result-
ing gas or mixture at the original temperature and
pressure?

8. How many 1. of oxygen are required in order to
burn completely 4 g. of sulphur, and how many 1. of
sulphur dioxide will be formed ?

9. What weight of water will be produced by burn-
ing 5 1. of hydrogen ?

10. What weight of HC1 would result upon burning
1 1. of hydrogen in chlorine ?

11. How many cc. of air are necessary to burn a
mixture containing 375 cc. of marsh gas and 450 cc.
of olefiant gas (C2H4), and how much carbon dioxide
and aqueous vapor are produced ?

12. By the combustion of 1 cc. of sulphuric ether
having a sp. gr. of 0.72, how many cc. of carbon dioxide
and of aqueous vapor are produced, and how much
oxygen is consumed ?

13. After liberating, by chlorine, the iodine in
265 cc. of hydriodic acid, there were 318 cc. of a mix-
ture of hydrochloric acid and chlorine. What was the
volume of each gas in the mixture ?

14. How many 1. of air (21 % O) ought to be mixed
with 100 volumes of " fire damp" to supply material for
the complete combustion of this gas during explosion ?

15. If 40 g. of ammonia and 40 g. of HBr are
brought together, what weight of ammonium bromide
results ? What is left over, and what is its volume at
+ 220° F. and 768 mm.?

COMBINING VOLUMES OF GASES 109

16. How many 1. of air at 4- 20° C. and 780 mm. are
required for the complete combustion of 16 1. of me-
thane ; of ethylene ; of acetylene ; of carbon monoxide ;
of ammonia; of hydrogen sulphide?

17. If 1000 g. of bromine are to be united with hy-
drogen, what volume of hydrogen is needed at + 450° C.
and 766 mm. ? What volume of products results?

18. If 50 1. of hydrogen and 30 1. of chlorine are
mixed and exploded, what volume of hydrogen chloride
is produced? What gas and how much remains in
excess ?

19. What volume of hydrochloric acid would result
from the complete combination of 50 1. of chlorine with
hydrogen, the final temperature and pressure being the
same as the initial?

20. What volume of hydrogen would combine with
20 1. of oxygen? How many 1. of water vapor would
result?

21. How many 1. of oxygen will combine with 20 1.
of nitric oxide, and what volume of nitrogen peroxide
would be formed?

22. What volume of carbon dioxide will result from
the combustion of 27.4 1. of carbon monoxide?

23. What volume of oxygen is necessary to com-
pletely burn 40 1. of the vapor of benzene, and how
many 1. of carbon dioxide and water vapor would be
formed ?

24. In a eudiometer 88 cc. of hydrogen and 132 cc.
of chlorine are exploded by a spark ; what volume of
hydrochloric acid is formed, and what volume of uncom-
bined gas will remain?

110 PROGRESSIVE PROBLEMS IN CHEMISTRY

25. What volume of oxygen is required to burn 1 1.
of the vapor of alcohol to carbon dioxide and water?

26. What volume of oxygen is required to burn com-
pletely 175 cc. of acetylene ?

27. If ammonia and chlorine react to form nitrogen
and hydrochloric acid, what volume of chlorine is re-
quired to react completely with 160 1. of ammonia, and
what volumes of nitrogen and hydrochloric acid result?

28. 31. of a mixture in equal volumes of CH4, C2H4,
and CO are burned, the products being H2O and CO2.
How much oxygen is required and how much CO2 is
formed ?

29. If 7 1. of hydrogen are mixed with 8 1. of oxygen
and burned so far as possible, what volume of the prod-
uct (as a vapor) is formed and what is left uncom-
bined ?

so. What volumes of gases will be left if 3 1. of CH4
and 2 1. of air are caused to unite, so far as possible ?

31. What volumetric mixture of acetylene and air
would be most dangerously explosive ?

32. Show the relative volumes of the five gases pres-
ent when alcohol vapor burns in air.

33. How many 1. of hydrochloric acid and of oxygen
can be made by the use of 875 g. of water? How many
1. of chlorine are required ?

34. How many 1. of air are necessary to burn 150 g.
of benzol? Composition of air is oxygen 20.96% and
nitrogen 79.04%.

35. When 30 1. of hydrogen were mixed with 18 1.
of oxygen and chemical union was produced, how much
aqueous vapor having a temperature of + 140° C. and

COMBINING VOLUMES OF GASES 111

760mm. was obtained? Which gas remained in excess,
and what was its volume at the temperature and pres-
sure given above ?

36. How many 1. of oxygen would be required to
burn 101. of H2S?

37. How many 1. of oxygen will combine with 10 1.
of nitric oxide, and what volume of nitrogen peroxide
will be formed ?

38. If nitrogen and hydrogen could be made to com-
bine completely, what volume of each would be required
to form 10 1. of gaseous ammonia?

39. What volume of hydrogen and of oxygen at
-f 100° C. would combine to form 1 1. of steam?

40. If 1000 1. of ammonia gas are decomposed, what
volume of nitrogen and of hydrogen result if measured
at -10°C. and 600mm.?

41. If 30 cc. of hydrogen are mixed with 40 cc. of
air that contains 20 % of oxygen, and the mixture is
ignited, what gases remain after explosion and what
is the volume of each?

42. A mixture of 10 cc. of hydrogen and 10 cc. of
chlorine, exploded by an electric spark, yields 20 cc. of
hydrogen chloride. Show how this indicates that the
molecule of hydrogen consists of at least two atoms.

43. If 2 volumes of ethylene weighing 28 g. are
burned in air, what volumes of nitrogen and of other
gases result?

44. After 72 cc. of NH3 are decomposed by electri-
city, 100 cc. of oxygen are introduced and the mixture
is exploded; what gases remain and how much of
each ?

112 PROGRESSIVE PROBLEMS IN CHEMISTRY

45. One Kg. of carbon disulphide is burned in oxygen.
What weight of oxygen is needed, and what is the volume
of each of the products formed at + 20° C. and 760 mm.?

46. When 150 cc. of oxygen are mixed with 400 cc.
of hydrogen and the mixture is exploded, what volume
of steam is produced? Which gas, and how much of
it, remains uncombined?

47. If 50 cc. of hydrogen are exploded with 75 cc. of
oxygen, what is the total volume of the gases after the
explosion, measured at -f 150° C. and 760mm. pressure?

48. When 40 1. of CO are burned, what is the volume
of CO2 produced?

49. What volumes of the components would yield
100 g. of nitrogen tetroxide ?

50. If 500 cc. of oxygen are exploded with 250 cc.
of hydrogen, what gas, if any, will remain and how much
of it?

51. How much oxygen will be required for the com-
plete combustion of 10 g. of stibine and arsine, re-
spectively ?

52. How many 1. of oxygen are contained in 3 1. of
nitrogen tetroxide?

53. If 20 g. of MnO2 are boiled with an excess of
hydrochloric acid until all the MnO2 is decomposed,
and the resultant chlorine is united with hydrogen,
what volume of H is needed, and what volume of HC1
results if both are measured at + 45° C. and 746 mm. ?

54. What volume of oxygen is required for the com-
bustion of 575 cc. of AsH3?

55. How many cc. of hydrogen and nitrogen are con-
tained in a 1. of ammonia gas ?

COMBINING VOLUMES OF GASES 113

56. If 100 volumes of air containing 21 volumes of
oxygen are mixed with 70 volumes of hydrogen, and an
electric spark is passed through the mixture, what will
be the volume of the gas remaining and of what will it
consist ?

57. If 50 cc. of hydrogen are exploded with 45 cc. of
oxygen, what is the total volume of the gases after the
explosion, measured at -f- 150° C. and 760 mm. pressure?

58. How many cc. of hydrogen and nitrogen are
contained in 1 m.3 of ammonia gas?

59. How many 1. of hydrogen can be obtained from
61. of HC1?

60. One ft.3 of hydriodic acid is decomposed by an
excess of bromine. How many ft.3 of hydrobrornic
acid are formed?

61. What volume of oxygen is required for the com-
plete combustion of 101 g. of SbH3?

62. If 50 cc. of air are mixed with 25 cc. of hydro-
gen and exploded in a eudiometer, what volume will
the remaining gas occupy and of what will it consist?

63. What weight of oxygen is required for the com-
plete combustion of 24 1. of phosphine, measured at
+ 15° C. and 740 mm. pressure?

64. An unknown volume of hydrogen sulphide re-
quired 157 cc. of oxygen for complete decomposition.
What was the volume of the hydrogen sulphide?

65. A mixture of 300 cc. of methane and 150 cc. of
oxygen was exploded. What was the volume of the
product after the removal of aqueous vapor (by absorp-
tion), temperature being + 100° C. and pressure 760mm.
constant throughout?

114 PROGRESSIVE PROBLEMS IN CHEMISTRY

66. A mixture of 250 cc. of carbon monoxide and
120 cc. of oxygen was exploded. Calculate the volume
of gaseous product.

67. A mixture of 420 cc. of hydrogen and 180 cc. of
oxygen was exploded. What was the volume of prod-
uct after the removal of aqueous vapor (by absorption
with phosphorus pentoxide), temperature being -f 100°
C. and pressure of 760mm.?

68. If 17 1. of NH3 are decomposed, how many 1.
will there be of resultant gases ?

69. A mixture of 200 cc. of carbon monoxide and
300 cc. of oxygen was exploded over mercury. Cal-
culate the volume of product, at + 27° C. and pressure
of 740 mm. constant throughout.

70. A mixture of oxygen and hydrogen measuring
250 cc. was exploded. The volume of product meas-
ured 76.47 cc., at +17° C. and pressure of 754.4 mm.
Calculate the volumes of hydrogen and oxygen.

71. A mixture of 320 cc. of carbon monoxide and
1800 cc. of oxygen was exploded. Calculate the
volume of gaseous product after the removal of the
carbon dioxide (absorption by lime).

72. A mixture of 80 cc. of methane and 200 cc. of
oxygen was exploded over mercury. Calculate the
volume of product, at temperature of + 20° C. and
barometric pressure of 757.4 mm. constant.

73. A mixture of 490 cc. of hydrogen and 1300 cc.
of oxygen was exploded. . Calculate the volume of
product, at temperature of -}- 25° C. and pressure
753.6 mm. constant.

i

COMBINING VOLUMES OF GASES 115

74. When 250 cc. of dry air were mixed with 150 cc.
of hydrogen and exploded, the volume of product was
350 cc. Calculate the percentage of oxygen in the
sample of air. Temperature of -f 100° C. and atmos-
pheric pressure remained constant.

75. A mixture of hydrogen sulphide with an excess
of oxygen measured 350 cc. at + 160° C. and 750 mm.
pressure. \ After explosion (with complete combustion),
the volume of dry gaseous product read 260 cc. at
these same conditions. Calculate the volume of hydro-
gen sulphide in the mixture.

76. Find the proportions by weight and by volume
in which ethane will combine with oxygen.

77. A volume of nitric oxide, measuring 400 cc., was
required for the combustion of a definite weight of
phosphorus. What volume of nitrogen remained free?

78. What volume of water gas is theoretically possible
from the action of 1 1. of steam upon heated coke ?

79. In the decomposition of methane by chlorine,
what volume of hydrogen chloride corresponds to 1 vol-
ume of methane ?

80. A mixture of 400 cc. of methane and 1000 cc.
of chlorine was exploded. Calculate the volume of
gaseous product.

81. How many 1. of air are required for the com-
plete combustion of 10 1. of (ft) marsh gas ; (6) olefiant
gas ; (c) acetylene ?

82. If 5 1. of chlorine are mixed with 5 1. of carbon
monoxide, what volume of phosgene gas is produced,
and how much hydrochloric acid and carbon dioxide
would be produced by the decomposition of this gas
with water ?

116 PROGRESSIVE PROBLEMS IN CHEMISTRY

83. If 5 1. of carbon monoxide are burned, what
volume of oxygen will be used, and what volume of
carbon dioxide will be formed ?

84. If an electric spark is passed through a mixture
of 5 volumes of carbon monoxide and 3 volumes of
oxygen, what diminution in bulk will be observed ?

85. If 50 cc. of carbon monoxide are mixed with
20 cc. of oxygen and exploded, and the resulting
mixture is then shaken up with sodium hydrate, what
volume of gas will remain and what gas will it be ?

86. Carbon is burned in 220 1. of oxygen; what
volume of carbon dioxide will be formed ?

87. If 50 cc. of nitrous oxide are decomposed into
nitrogen and oxygen, how many cc. of each will be
formed ?

88. A mixture of acetylene with an excess of oxygen
measured 350 cc. at + 25° C. and 745 mm. pressure.
After explosion the volume of dry gaseous product read
275 cc. under the same conditions. Calculate the volume
of acetylene in the mixture.

89. A mixture of acetylene with an excess of oxygen
measured 240 cc. at + 24° C. and 752.4 mm. pressure.
After explosion the volume of product read 221.8 cc.
at -f 28° C. and 750.1 mm. pressure. Calculate the
volume of acetylene in the mixture.

90. If 600 volumes of carbon monoxide are mixed
with 600 volumes of oxygen, an electric spark is passed
through the mixture, and then a solution of caustic
potash is added, what volume of gas will be ab-
sorbed and of what will the residue, if there is any,
consist?

COMBINING VOLUMES OF GASES 117

91. How many volumes of oxygen are required for
the complete combustion of 1 1. of each of the following :
(a) CO; (6) CH4; <» C2H4; (d) C2H2 ; <» H2S ;

92. If 500 cc. of hydrogen at + 39° C. are exploded
with 500 cc. of oxygen under a pressure of 332.5 mm.,
what volume of which gas is left ?

93. How many 1. of oxygen will be required to burn
50 1. of C2H4 and how many of CO2 will form ?

94. If 10 ft.3 of H2S are burned, what volume of each
product will be formed ?

95. I have 5500 cc. of CO2 formed by the combustion
of CO in air. How much air was required and how
much CO ?

96. State the volume of the products resulting from
the combustion of 2.5 1. of carbon disulphide gas.

97. What volume of products results from the de-
composition of 100 1. of ammonia ?

98. One million molecules of hydrogen will unite
with how many molecules of oxygen to form how many
molecules of water ? What will be the relative weights
of hydrogen and water ?

99. A mixture of 10 cc. of chlorine and 10 cc. of
hydrogen, exploded by an electric spark, yields 20 cc.
of hydrogen chloride. Show how this indicates that
the molecule of hydrogen consists of at least 2 atoms.

CHAPTER IX

Calculation of Formulas

1. A compound has the following percentage com-
position: carbon, 37.61% ; hydrogen, 12.53% ; oxy-
gen, 49.86%. One 1. of its vapor weighs 1.4339 g.,
What is its formula ?

2. A gas has the following composition : carbon,
27.39%; oxygen, 72.60%. Its density (air) is 1.52.
What is its formula ?

3. What is the simplest formula of a substance
which consists of oxygen, 88.83%, and hydrogen,
H.11%?

4. Calculate the simplest formula of mercuric oxide,
which contains 92.59 % of mercury and 7.41 % of oxygen.

5. What is the simplest formula of a substance
consisting of calcium, 29.49% ; sulphur, 23.59% ; and
oxygen, 46.92%?

6. The percentage composition of a mineral is found
to be: calcium, 40.12% ; carbon, 12.04%; and oxy-
gen, 47.84%. What is its simplest formula?

7. Acetic acid consists of carbon, 40 % ; hydrogen,
6.67%; and oxygen, 53.33%. Its vapor density is
30. What is its molecular formula ?

8. What is the molecular formula of the gas having
the composition : nitrogen, 30.43 % : oxygen, 69.57 % ?
The weight of 1 1. is 2.061 g.

118

CALCULATION OF FORMULAS 119

9. What is the molecular formula of the gas having
the density 197 and the composition: iodine, 96.70%;
carbon, 3.05% ; hydrogen, 0.25%?

10. In 100 parts of a compound of manganese and
oxygen there are 63.22 parts of manganese and 36.78
parts of oxygen. What is the simplest formula possi-
ble?

11. Calculate the formulas of the following :

Ba = 58.80 K = 31.91 Ca = 40.00 Ag = 75.27
8 = 13.75 01 = 28.94 0 = 12.00 01 = 24.73
O = 27.45 O = 39.15 O = 48.00

12.

K = 38.68

N = 13.89

Mg = 21.65
P = 27.92

K = 16.00
Pt = 40.41

Na=18.54
8 = 25.84

0=47.43

O = 50.43

01 = 43.59

H= 0.81

0 = 25.79

H2O = 29.02

13.

Na = 18.54 CaO= 9.20 Fe = 72.41

8 = 25. 84 A12O3 = 16.85 O = 27. 59

H= 4.03 Si02 = 59.29 Mn = 71.69

O = 51.59 H2O = 14.66 O = 28.31

14.

Cu = 34.46 CaO = 43.45 Ag = 53.15 Lithia = 6.43

Fe = 30.59 A12O3 = 17.68 Cu = 31.08 Alumina = 29.26

8 = 34.95 SiO2 = 38.87 8 = 15.77 Silica = 64.31

15.

Pb = 76.36

0 = 21.03

0 = 52.17

K = 42.41

P= 6.86

H= 2.63

H = 13.04

Fe = 15.22

01= 2.62

K = 34.27

O = 34.79

0 = 19.56

O = 14.16

O = 14.03

N = 22.81

8 = 28.04

120 PROGRESSIVE PROBLEMS IN CHEMISTRY

16.

0 = 90.57 0 = 89.55 0 = 79.73 Si = 19.50

H = 9.43 H = 10.45 H= 6.32 0 = 66.62

N= 13.95 H = 13.88

17.

0 = 75.46 H = 6.59 N = 8.38 O = 9.57

18. Find the formula of that nitrate which gave, by
analysis, 62.45% lead, 8.68% nitrogen, and 28.85%
oxygen.

19. Derive the formula of that substance which gave,
by analysis, 52.02% carbon, 13.20% hydrogen, and
34.68% oxygen.

20. What is the formula of that acetate which gave,
by analysis, 63.61 % lead, 14.62 % carbon, 1.98 % hydro-
gen, and 19.79% oxygen?

21. An oxide of iron gave, by analysis, 69.80 % iron ;
what is the formula?

22. An oxide of barium gave, by analysis, 81 %
barium ; what is the formula?

23. The vapor density of a gas is 13.91. The analy-
sis gives the following composition: 0 = 85.62 and
H = 14.38. What is the formula? Find the weight
of 11.

24. Derive the formula of the oxide produced when
6.87 g. of barium unite with 1.6 g. of oxygen.

25. Find the formula of the oxide formed in the
combustion of 2.61 g. of aluminum with oxygen to a
final weight of 5.01 g.

26. What is the formula of the oxide produced by the
combustion of 43.45 g. of lead with 4.48 g. of oxygen?

CALCULATION OF FORMULAS 121

27. Derive the formula of the oxide produced by the
burning of 2.5 g. of phosphorus in oxygen to a final
weight of 5.7 g.

28. Calculate the formulas of :

00 (*)

N = 22.05 Si02 = 23.53

C = 14.18 CaO= 1.90

O = 56.68 A12O3 = 37.72

H= 7.09 Water = 36.85

29. What will be the formula of a hydrocarbon that
contains twice as many hydrogen atoms as carbon, and
the vapor of which has a density of 1.947?

30. Find the simplest formula for acid potassic car-
bonate, its percentage composition being : hydrogen,
1.00; potassium, 39.06; carbon, 11.99; oxygen, 47.95.

31. In 100 parts of crystallized ferrous sulphate there
are 20.15 parts of iron, 11.51 parts of sulphur, 23.02
parts of oxygen, and 45.32 parts of water; what is its
simplest formula?

32. What is the simplest formula of morphia, its
percentage composition being: carbon, 71.58; hydrogen,
6.66; nitrogen, 4.91; oxygen, 16.85?

33. Derive the formula of crystallized sodium sul-
phate, 8.16 g. of which lost 4.51 g. of water upon
dehydration.

34. Find the formula of crystallized copper sulphate,
7.84 g. of which lost 2.79 g. of water upon heating.

35. Calculate the formula of crystallized aluminum
sulphate, 9.54 g. of which lost 4.61. g. of water upon
heating.

122 PROGRESSIVE PROBLEMS IN CHEMISTRY

36. Work out the formula of aluminum hydroxide,
4.75 g. of which lost 1.64 g. of water and left a residue
of AL03.

L 6

Deduce the formulas of the following substances :

37. Magnesium, 9.76; sulphur, 13.01; oxygen,
26.01; water, 51.22.

38. Zinc, 22.70; sulphur, 11.15; oxygen, 22.28;
water, 43.87.

39. Sodium, 32.79; aluminum, 13.02; fluorine, 54.19.

40. Aluminum, 16 ; sulphur, 28 ; oxygen, 56.

41. Copper, 57.46; carbon, 5.43; hydrogen, 0.91;
oxygen, 36.20.

42. Hydrogen, 3.18; oxygen, 33.88; nitrogen, 14.84;
sulphur, 16.95; nickel, 31.15.

43. Carbon, 19.04; hydrogen, 4.76 ; sulphur, 25.40;
oxygen, 50.80.

44. Carbon, 46.66; hydrogen, 4.26; nitrogen, 5.20;
oxygen, 5.92; platinum, 18.26 ; chlorine, 19.70.

45. Calculate the formula of the nitrate, 19.7 g. of
which were prepared from 10.4 g. of bismuth.

46. Find the formula of that chlorate, 4.165 g. of
which lost 1.3 g. of oxygen upon heating and gave a
residue of barium chloride.

47. What is the formula of mercuric cyanide, 5.4 g.
of which lost 1.1 g. of cyanogen upon heating?

48. Derive the formula of the double salt of ammo-
nium sulphate and copper sulphate, 4.12 g. of which
lost 1.81 g. of ammonium sulphate upon heating.

49. The vapor density of steam is 9. The percent-
age composition of water is : hydrogen, 11.11 ; oxygen,
88.89. What is the formula of water ?

CALCULATION OF FORMULAS 123

50. The vapor density of alcohol vapor is 23. In
100 parts there are 52.18 parts of carbon, 13.04 parts
of hydrogen, and 34.78 parts of oxygen. What is the
formula of alcohol ?

51. The vapor density of the vapor of ethylene chloride
is 49.5, and its percentage composition is: carbon, 24.24;
hydrogen, 4.04 ; chlorine, 71.72. What is its formula?

52. The vapor density of a certain gas is 13.91, or the
weight of a 1. of this gas at 0° C. and 760 mm. pressure
is 1.26 g. (Use only one of these weight relations.) The
analysis of this gas gave the following percentages:
carbon, 85.62; hydrogen, 14.38. What is the formula?

53. Analysis of a compound gave : lead, 68. 30 % '•>
sulphur, 10.55%; oxygen, 21.15%. Calculate the em-
pirical formula.

54. Calculate the empirical formulas from the follow-
ing analytical results : potassium, 52.45 % ; chlorine,
47.55 % - Arsenic, 41.32 % ; chlorine, 58.66 % . Sodium,
32.43%; hydrogen, 0.71%; phosphorus, 21.82%;
oxygen, 45.04 %. Potassium, 35.56 % ; iron, 17.00 % ;
cyanogen, 47.44 % . Magnesium, 21. 82 % ; phosphorus,
27.86% ; oxygen, 50.32%.

55. Aldehyde has the following composition : C,
54.67%; H, 9.11%; and O, 36.22%. The density
(air) of its vapor is 1.526. What is its formula?

56. Butyric acid has the same percentage composi-
tion as an aldehyde, but the density (air) of its vapor
is 3.052. What is its formula ?

57. Analysis of a compound gives 26.67 % C, 2.22 %
H, and 71.11 % O ; what is its simplest formula ? If that
is the correct one, what should be the vapor density of
the gas ?

124 PROGRESSIVE PROBLEMS IN CHEMISTRY

58. A compound consists of 5.88 % H and 94.12 % O ;
find the smallest formula that can apply to it.

59. An ore of iron analyzes 70 % Fe and 30 % O :
what formula should it have ?

60. Zinc is obtained from its sulphide, a specimen of
which contains 67.01% Zn and 32.99% S. Ascertain
the formula of zinc sulphide.

61. Find the formula of a hydrocarbon that contains
an equal number of hydrogen and carbon atoms, and
the vapor of which has a density (air) of 0.9.

62. Formic acid has the composition: C, 26.21%;
O, 69.43% ; and H, 4.36%. The density (air) of its
vapor is the same as that of alcohol. Find the formula.

63. Find the formulas of the following two substances :

00 (0

Bi = 42.99 K= 8.24

O = 29.74 Al= 5.69

N= 8.67 8 = 13.50

Water = 18.60 O = 27.01

Water = 45. 56

64. Oxalic acid consists of C, 26.79%; H, 2.23%;
and O, 70.98 %. Find the formula.

65. Alcohol is C, 52.28; O, 34.64; and H, 13.08.
Calculate the formula.

66. Deduce the formulas of the following :

00 (*)

Fe = 20.15 K= 7.77

8 = 11.51 Mn = 10.95

O = 24.02 8 = 12.75

Water = 44. 32 O = 25.48

Water = 43. 05

CALCULATION OF FORMULAS 125

67. Red lead consists of Pb, 90.65 % ; and O, 9.35 %.
What is the formula ?

68. The sp.gr. of mercurous chloride is 7. It con-
tains 84.92 % of Hg and 15.08 % of chlorine. To what
formula would this correspond ?

69. Calculate the formula of the following :

Na = 14.41 Sb = 25.05 8 = 26.72 Water = 33.82

70. Calculate the formulas from the following per
cents: calcium, 38.72; phosphorus, 20.00; oxygen,
41.28.

71. Potassium, 28.73; hydrogen, 0.73; sulphur,
23.52; oxygen, 47.02.

72. Potassium, 45.95; nitrogen, 16.45; oxygen,
37.60.

73. Aluminum, 16 ; sulphur, 28 ; oxygen, 56.

74. Carbon, 85.71; hydrogen, 14.29.

75. Carbon, 92.3; hydrogen, 7.7.

76. One volume of a gaseous hydrocarbon at
-f 100° C. yields on combustion double its volume of
CO2 and 3 times its volume of steam at the same tem-
perature. Find the formula of the gas.

77. A compound has the following composition :
phosphorus, 20.22%; oxygen, 10.43%; chlorine,
69.35%. The density (air) of its vapor is 5.295.
What is its formula?

78. If an iron ammonium sulphate contains \ of its
weight in iron, find the formula.

79. A compound has the following composition :
phosphorus, 22.58% ; chlorine, 77.42%. One 1. of the
vapor weighs 6.13 g. Calculate the formula.

126 PROGRESSIVE PROBLEMS IN CHEMISTRY

80. Calculate the formulas of the substances pos-
sessing the following percentage compositions :
Magnesium = 25.57 Sodium =32.43 Potassium = 26.585

Chlorine = 74.43 Sulphur = 22.55 Chromium = 35.390
Oxygen = 45.02 Oxygen = 38.025

81. Find the formula when Zn = 22.67; S = 11.15;
O = 22.29; and water = 43. 89.

82. Calculate the formula when Zn = 54.14;
Si = 11.67 ; O = 26.67 ; and water = 7.52.

83. Assign formulas to the following :

00 0)

CO = 22. 74 A12O3 = 16.86

N = 26.96 CaO= 9.20

Cl = 41.05 SiO2 = 59.28

H= 5.78 Water = 14. 66

Water = 3.47

84. Calculate the formulas from the following per
cents: carbon, 19.04; hydrogen, 4.76; sulphur,
25.40; oxygen, 50.80.

85. Carbon, 74.07; hydrogen, 8.64; nitrogen, 17.29.

86. Carbon, 46.66 ; hydrogen, 4.26; nitrogen, 5.20;
oxygen, 5.92; platinum, 18.26; chlorine, 19.70.

87. Lime, 28.4; magnesia, 12.3; iron monoxide,
12.3; manganese monoxide, 1.9; carbon dioxide, 44.4.

88. A mineral gave the following numbers on analysis :
SiO2, 46.96; MgO, 31.26; H2O, 21.22. Calculate its
formula.

89. A specimen of cobalt bloom was found to have
the following composition: As2O5, 38.43; CoO, 36.52 ;
FeO, 1.01; H2O, 24.14. Determine its formula.

CALCULATION OF FORMULAS 127

90. One hundred OG. of ammonia gas are completely
decomposed by a series of electric sparks, yielding
200 cc. of mixed hydrogen and nitrogen. An excess
of oxygen is next added, when the volume of mixed
gases is found to amount to 290 cc. The mixture is
now exploded, when 65 cc. of gas remain. Show from
these data that the formula for ammonia is NH3.

91. Ca = 40; C = 12; O = 48. Calculate the
simplest formula. Find the percentage composition
of C in this formula to see if your answer is correct.

92. Calculate the molecular formula of a substance
having the following composition: carbon, 74.1%;
hydrogen, 8.6 % I nitrogen, 17.3 %. The vapor density
is 81.

93. C = 10.04%; H = 0.83%; Cl = 89.13%; and
the vapor density is 59.75. Find the formula.

94. On analysis, 18 g. of a compound of iron and
sulphur yielded 8.4 g. of iron and 9.6 g. of sulphur;
what is its simplest formula ?

95. On analysis, 48 g. of a compound yielded 37.21 g.
of lead, 2.16 g. of carbon, and 8.63 g. of oxygen; what
is its simplest formula?

96. What is the simplest formula of a substance,
27 g. of which, on analysis, yielded 2.64 g. of magne-
sium, 3.51 g. of sulphur, 7.02 g. of oxygen, and
13.83 g. of water?

97. A compound of arsenic and oxygen is composed of
75+%As, 24+% O; what is its smallest formula? Its
vapor density being 198, what should be its true formula?

98. A compound of hydrogen and carbon has 92.3%
C and 7.7 % H. Find its smallest formula. The density
being 13, what is the proper formula?

128 PROGRESSIVE PROBLEMS IN CHEMISTRY

99. An analysis of a salt gave the following per-
centage numbers: S, 22.53; Na, 32.39; O, 45.08.
What is its empirical formula?

100. A salt on analysis gives the following percent-
age numbers: N, 9.09; O, 20.77; Ag, 70.13. Calcu-
late the simplest formula for this body.

101. Calculate the formula for a body which has the
following percentage composition: oxygen, 38.1; hy-
drogen, 0.8; phosphorus, 24.6 ; sodium, 36.5.

102. Calculate the formula of a body which has the
following percentage composition: magnesium, 3.98;
calcium, 13.28; potassium, 12.99; sulphuric acid
(SO4), 63.77; water, 5.98.

103. Find the formula of the following : O, 48 % ;
S, 24%; andFe, 28%.

104. A substance contains carbon, 20 % ; oxygen,
26.6%; and sulphur, 53.3%. Find its formula.

105. Find the formulas of the following minerals :

00 (ft)

SiO2= 65.69 N2O = 4.21

A12O3 = 17.97 CaO = 12.93

CaO= 1.34 A12O3= 30.68

N20= 1.01 Si02 = 39.99

K20 = 13.99 H20 = 12.19

106. Calculate the formulas :

00 (ft)

A12O3 = 58.66 SiO2 = 47.24

SiO2 = 34.20 MnO2 = 31.50

F= 7.14 Water =21. 26

CHAPTER X

Atomic and Molecular Weight Calculations

1. Ten 1. of a gas weigh 17.92 g. ; find its molecular
weight.

2. The sp. gr. of hydrogen iodide is 4.4; calculate
its molecular weight.

3. Find the molecular weight of the gas of which
20 g. occupy 9.9 1. under 1.5 atmospheres pressure at
+ 17°C.

4. One hundred g. of lead form 146.45 g. of lead
sulphate; find the molecular weight of sulphuric acid.

5. The vapor of a compound is found to be thirty-
nine times as heavy as hydrogen at the same tempera-
ture and pressure. What is the molecular weight of
the compound?

6. A 1. of nitrous oxide weighs 1.97 g. ; find its
molecular weight.

7. Find the molecular weight of the gas the density
of which is 1.524.

8. A 1. of ammonia, under standard conditions,
weighs 0.76 g. ; find its molecular weight.

9. A 1. of nitrous oxide, under standard conditions,
weighs 1.97 g. ; find its molecular weight.

10. A 1. of cyanogen, under standard conditions,
weighs 2.33 g. ; find its molecular weight.

129

130 PROGRESSIVE PROBLEMS IN CHEMISTRY

11. A 1. of ethane, under standard conditions, weighs
1.34 g. ; find its molecular weight.

12. Find the molecular weight of the gas the density
of which is 1.108.

13. A 1. of arsine weighs 3.49 g. under standard
conditions ; find its molecular weight.

14. Find the molecular weight of the gas the density
of which is 0.623.

15. Calculate the molecular weights of the following
gases :

one 1. of ethane weighs 1.34 g. ;

one 1. of hydrogen sulphide weighs 1.52 g.;

one 1. of nitric oxide weighs 1.34 g.;

one 1. of phosphine weighs 1.52 g. ;

one 1. of carbonyl chloride weighs 4.42 g. ;

one 1. of SiF4 weighs 4.68 g. ;

one 1. of butane weighs 2.59 g.

16. The weight of 3840 cc. of a certain vapor, at
standard conditions, is 24 g. ; what is the molecular
weight of the substance ?

17. If 3180 cc. of a gas, measured at + 24° C. and 750.2
mm. pressure, weighed 6 g., what is the molecular weight?

18. The vapor density of a gas is 44 ; find its mo-
lecular weight, sp. gr., and the weight of 1 1.

19. Calculate the molecular weights of the following
gases:

the density (referred to air) of ammonia is 0.59;

the density (referred to air) of HF is 0.69;

the density (referred to air) of methyl alcohol is 1.11 ;
the density (referred to air) of mercury vapor is 6.91;
the density (referred to air) of HI is 4.42.

ATOMIC AND MOLECULAR WEIGHTS 131

20. Find the molecular weights of the following
bodies: (air = l)
cadmium at + 940° C., relative density = 3.94 ;
phosphorus at + 500° C., relative density = 4.35 ;
mercury at + 446° C., relative density = 6.98.

21. Determine the molecular weights of the follow-
ing gases from the data annexed: nitrogen; 2 1. weigh
2.51 g.

22. Carbon monoxide; 1500 cc. weigh 1.88 g.

23. Carbon dioxide ; 500 cc. weigh 0.98 g.

24. One 1. of SO2 weighs 2.86 g. ; what is its molec-
ular weight?

25. The weight of 1| 1. of CO is 1.88 g.; calculate
the molecular weight.

26. What is the molecular weight of marsh gas, 3 1. of
which weigh 2.15 g.?

27. Sulphur dioxide is 2.22 times as heavy as air;
find its density and molecular weight.

28. If 30 g. of a gas occupy 52.7 1. under 0.5 atmos-
pheric pressure at -f 27° C., what is the molecular weight
of the gas?

29. A quantity of gas measuring 5.4 1., when the
temperature is + 15° C. and pressure 740 mm., weighs
7.6 g. ; what is its molecular weight?

30. The vapor density of a gas was 31.17 when its
temperature was + 11° C. and under a pressure of 750
mm.; what is its molecular weight?

31. Calculate the molecular weights of the following
gases from their vapor densities: (a) chlorine, 35.5;
(5) hydrochloric acid, 18.25; (e) ammonia, 8.5;
nitrogen, 14; (e) steam, 9.

132 PROGRESSIVE PROBLEMS IN CHEMISTRY

32. Berzelius found that 4.20775 parts of MnCl2
yielded 9.575 parts of AgCl ; what is the atomic weight
of silver?

33. By analysis we find that for every 100 parts of
silver bromide there are 57.44 parts of Ag and 42.56
parts of Br. The atomic weight of Br = 79.8. What
is the atomic weight of silver?

34. We find from analysis that barium chloride con-
tains 65.86% of Ba and 34.14% of Cl. There are no
compounds of Ba the vapor density of which has been
determined. The specific heat of Ba being unknown,
how would you determine the atomic weight of Ba?

35. Marignac found that 3.8844 g. NaCl were re-
quired for the precipitation of 11.308 g. of AgNO3 ;
find atomic weight of nitrogen.

36. By heating 15 g. of pure silver in a stream of
chlorine, 19.9306 g. of silver chloride are produced.
The weight of the atoms of silver in a molecule of silver
chloride is 108. What is the molecular weight of sil-
ver chloride and the number of atoms of chloride in a
molecule?

37. If 3.17 g. of iron form 4.53 g. of Fe2O3, what is
the atomic weight of iron ?

38. If 8019 cc. of a gas, measured over water at
+ 20° C. and 742.4 mm. pressure, weighed 14 g. when
deprived of aqueous vapor, what is the molecular weight ?

39. If 5647 cc. of a gas, measured over water at
+ 24° C. and 754.2 mm. pressure, weighed 6.254 g.
when deprived of aqueous vapor, what is its molecular
weight ?

ATOMIC AND MOLECULAR WEIGHTS 133

40. A compound of phosphorus, oxygen, and chlorine
contained 20.19% of phosphorus, 10.43% of oxygen,
and 69. 38% 'of chlorine. The vapor density of the
compound as gas = 77.95 and the specific heat of phos-
phorus = 0.202. Find the molecular formula of the
compound and the atomic weight of phosphorus.

41. The sp. gr. of phosphorus trichloride is 4.88;
what is its molecular weight?

42. Sodium chloride contains 39.32% of sodium
and its molecular weight is 58.5. What is the atomic
weight of sodium, on the supposition that there is but
1 atom of sodium in the molecule of salt ?

43. Berzelius obtained 17.554 g. of PbO from 16.2956
g. of lead ; find the atomic weight of lead.

44. CuO, when heated in hydrogen, lost 59.80 g. of
oxygen and formed 67.3 g. of water. If O = 16, what
is the atomic weight of hydrogen ?

45. Stas found that 91.46 g. of metallic silver, when
heated in a stream of chlorine, yielded 121.4993 g. of
pure silver chloride. Calculate from this the atomic
weight of chlorine.

46. Stas found, after adding 7.25682 g. of potassium
chloride to 10. 51995 g. of silver dissolved in nitric acid,
that 0.0194 g. of silver remained in solution. Calculate
from these data the atomic weight of potassium.

47. Erdmann and Marchand obtained 109.6308 g. of
mercury from 118.3938 g. of the red oxide. Calculate
the atomic weight of mercury.

48. If 0.3697 g. of aluminum liberated 0.04106 g. of
hydrogen on being dissolved in a strong solution of so-
dium hydrate, what is the atomic weight of aluminum ?

134 PROGRESSIVE PROBLEMS IN CHEMISTRY

49. Marignac found that 5 g. of strontium chloride,
containing 6 molecules of water of hydration, yielded
3.442 g. of strontium sulphate. Calculate the equivalent
of strontium.

50. Pure carbon monoxide was passed over red-hot
copper oxide; the residual metal and the carbon dioxide
formed were weighed; 24.360 g. of oxygen were lost
and 67.003 g. of carbon dioxide were obtained. From
this calculate the atomic weight of carbon.

51. One g. of an element is found to combine with
oxygen so as to form 2.9 g. of oxide; calculate its
equivalent.

52. If 0.254 g. of a metal, when dissolved in hydro-
chloric acid, liberated 116 cc. of hydrogen, measured
at + 15° C. and 725 mm., what is the equivalent of
the metal?

53. Phosphine contains 91.17 % of phosphorus and
8.83 % of hydrogen ; find the equivalent of phosphorus.

54. Three oxides of nitrogen contain, respectively,
63.63%, 46.66%, and 36.84% of nitrogen; calculate
the equivalent of nitrogen in each of them.

55. A bromide of antimony contains 66.66% of bro-
mine. If Br = 80, calculate the equivalent of antimony.

56. A 1 % sugar solution gives an osmotic pressure
of 516 mm. at -f 15° C. What is the molecular weight
of sugar? Assume that the sp. gr. of the solution is 1.

57. The specific heat of an element is -^ ; and its
atomic weight is a multiple of 14. Find the atomic
weight of the element.

58. If 200 parts of BaCl2 give 224.2 of BaSO4,
what is the atomic weight of barium ?

ATOMIC AND MOLECULAR WEIGHTS 135

59. The equivalent of lead is found to be 103.5 and
that of platinum 48.6; determine the probable atomic
weight of both lead and platinum, specific heat of lead
being 0.0310 and of platinum 0.0324.

60. A 1. of oxygen under standard conditions weighs
1.43 g. A 1. of a certain element, the molecule of
which contains 2 atoms, if vaporized under the same
conditions, would weigh 11.43 g. What is the atomic
weight of the element ?

61. When 2.16 g. of silver are treated with chlorine,
2.87 g. of AgCl are formed ; calculate the atomic weight
of silver.

62. If 10 g. of the chloride of a certain univalent
element are found to contain 60.6% of chlorine, and
if the atomic weight of chlorine is 35.5, what is the
atomic weight of the other element?

63. The molecular weight of potassium chloride is
74.2. The per cent of potassium in the compound is
52.56. The specific heat of potassium is 0.166. What
is the atomic weight of the element ?

64. The molecular weight of lead oxide. PbO, is
221.3. The per cent of lead = 92.81. Specific heat of
lead = 0.031. What is its atomic weight ?

65. A compound of hydrogen and sulphur has a
molecular weight of 34. The per cent of sulphur
in the compound is 94.11. Specific heat of sulphur
= 0.163. What is its atomic weight ?

66. A compound of aluminum and chlorine has a
molecular weight of 265.2. Per cent of aluminum is
20.36. Specific heat of aluminum = 0.222. What is
the atomic weight of aluminum ?

136 PROGRESSIVE PROBLEMS IN CHEMISTRY

67. Analysis of uranium chloride shows the com-
position: U, 62.7%; Cl, 37.3%. The specific heat
of metallic uranium is 0.027. What is the atomic
weight of uranium and what the formula of the chloride ?

68. Find the atomic weight of lead from the follow-
ing data : the molecular weight of lead sulphide is
249; in 100 parts of lead sulphide there are 83.13
parts of lead ; specific heat of lead is 0.031.

69. The molecular weight of arsenuretted hydrogen
is 78. In 100 parts there are 96.15 parts of arsenic,
and the specific heat of arsenic is 0.0814. What is the
atomic weight of arsenic ?

70. The molecular weight of carbon disulphide is
76, and 100 parts yield 84.21 parts of sulphur; the
specific heat of sulphur is 0.163. What is the atomic
weight of sulphur, and how many atoms of sulphur
are in a molecule of the carbon disulphide ?

71. The specific heat of silver is 0.056; what is its
atomic weight ?

72. If 35.5 g. of chlorine unite with 48.6 g. of
platinum to form platinic chloride and the specific heat
of platinum is 0.0324, what is (a) the atomic weight of
platinum and (6) the formula of platinic chloride ?

73. A compound consists of P, 20.19; O, 10.43;
Cl, 69.38. The vapor density of the substance in the
state of gas is 77.95; the specific heat of phosphorus
is 0.1887. Calculate the molecular weight of the com-
pound and the atomic weight of phosphorus.

74. Dumas found, on heating copper oxide in a
stream of dry hydrogen, that a certain weight of this

ATOMIC AND MOLECULAR WEIGHTS 137

substance lost 59.789 g. of oxygen and yielded 67.282 g.
of water. Calculate from these numbers the atomic
weight of hydrogen.

75. Marignac obtained 314.894 g. of silver nitrate
from 200 g. of silver. Further, 14.110 g. of silver
nitrate require 6.191 g. of. potassium chloride for com-
plete precipitation, and 10.339 g. of silver dissolved in
nitric acid require 5.120 g. of ammonium chloride for
precipitation. Calculate the atomic weight of nitrogen
from these data.

76. An oxide of bismuth contains 89.655% of bis-
muth ; calculate the equivalent of bismuth.

77. If 0.334 g. of metallic silver, dissolved in nitric
acid, yield a precipitate of silver chloride with hydro-
chloric acid which weighed 0.4436 g., what is the
equivalent of silver ?

78. If 3.2 g. of silver chloride, heated in a current
of hydrogen, yield 2.4081 g. of metallic silver, what is
the equivalent of silver ?

79. If 5 g. of copper oxide, heated in a current of
hydrogen, yield 3.9915 g. of metallic copper, what is
the equivalent of copper ?

80. If 1.665 g. of lead chloride were dissolved in
water, and silver nitrate was added to the solution, and
the precipitated silver chloride weighed 1.72 g., what is
the equivalent of lead ?

81. Mallet found that 8.2144 g. of ammonium alum,
dried by exposure to air at + 21° C. to + 25° C., yielded
0.9258 g. of A12O3. Taking the following atomic
weights: O, 15.961; S, 31.966; N, 14.010, find the
atomic weight of aluminum.

138 PROGRESSIVE PROBLEMS IN CHEMISTRY

82. Mallet found that 6.9617 g. of AlBr3 required
8.4429 g. of Ag for precipitation of the bromine. If
Ag= 107.649 and Br = 79.754, what is the atomic
weight of Al as deduced from this result ?

83. Find the equivalent of aluminum from the fol-
lowing data: (a) 5.2632 g. of the metal heated with
potash gave hydrogen which, when burned, yielded
5. 2562 g. of water; (6) 8.6492 g. of aluminum bro-
mide required 10.4897 g. of silver for complete precipi-
tation.

84. One 1. of mercury vapor at the standard tempera-
ture and pressure weighs 8.923 g. On heating 118.3938
g. of mercuric oxide, Erdmann and Marchand obtained
109.6308 g. of mercury. On the assumption that mer-
curic oxide is formed by the union of 1 atom of mercury
with 1 atom of oxygen, what light do these facts throw
on the atomic and molecular weights of mercury ?

85. By dissolving 0.4442 g. of metallic cobalt in an
acid, 177.4 cc. of hydrogen at + 10° C. and 750 mm.
pressure are obtained. The specific heat of the metal
is 0.107. Calculate the atomic weight of cobalt.

86. If 4.353 g. of potassium bromide required, for
complete precipitation, 3.946 g. of silver dissolved in
nitric acid, what is the equivalent of bromine ?

87. A compound has the following percentage com-
position: oxygen, 76.09%; hydrogen, 1.59%; nitro-
gen, 22.32%. One 1. of its vapor weighs 2.817 g.
What is its molecular weight and formula?

88. A hydrocarbon consists of carbon, 93.75%;
hydrogen, 6.25%. The density (air) of its vapor is
4.456. What is its formula ?

ATOMIC AND MOLECULAR WEIGHTS 139

89. A gas has the following composition : nitrogen,
30.56% ; oxygen, 69.44%. One 1. of the gas weighs
2.058 g. What is its molecular weight and formula ?

90. A compound has the following percentage com-
position: H, 1.19%; O, 56.86%; 01,41.95%. One
1. of its vapor weighs 3.771 g. What is its molecular
weight and formula?

91. If 4.5 g. of mercury unite with oxygen to form
4.86 of mercuric oxide, and the specific heat of mercury
is 0.032, what is its atomic weight?

92. If 25 g. of metallic tin were converted into
stannic oxide by heating with nitric acid and then ignit-
ing, and the stannic oxide weighed 31.8 g., what is its
atomic weight ? The specific heat of tin is 0.056.

93. Suppose that 0.3697 g. of aluminum liberated
0.04106 g. of hydrogen on being dissolved in a strong
solution of sodium hydrate. On the assumption that
alumina is a sesquioxide, A12O3, find from these data
the atomic weight of aluminum.

CHAPTER XI

Electro-chemical Problems

1. A current deposits 16 g. of silver; how much
copper will it deposit ?

2. What current strength (in amperes) is required
to deposit : 20 g. of silver in an hour ; 100 g. of iodine
in 5 minutes ; 60 g. of antimony in 3 hours ?

3. A current deposits 1 g. of sodium ; find weight
of Ni deposited.

4. If a current deposits 32 g. of Cu, how many g.
of Al, Na, Mg, Pb, will it deposit ?

5. Two electrolytic cells, one containing acidulated
water and the other lead nitrate solution, are joined
in series, and the same current is passed through them
until 25 cc. of hydrogen are liberated in the first cell.
What weight of lead nitrate will be decomposed in the
other cell ?

6. How many g. of silver will be deposited from a
solution of silver nitrate by a current of 2 amperes in
50 sec. ?

7. How many g. of copper will be deposited from
a bath of copper sulphate by a current of 5 amperes in
30 min. ?

8. How much would a metal platter increase in
weight if it were nickel-plated by a current of 0.5
ampere running 5 hr. ?

140

ELECTRO-CHEMICAL PROBLEMS 141

9. What is the current strength of a Daniell cell
if its copper plate gains 0.7 g. in 40 min. ?

10. How much current would be needed to make in
3 hr. a copper electrotype shell weighing 40 g. ?

11. How long would it take a current of 5 amperes
to produce 0.6 g. of hydrogen by decomposition of
water?

12. Find the electro-chemical equivalent for zinc
from the fact that one of the zinc plates in an Edison
chemical meter gains 726 g. when 20 amperes pass
through it for 30 hr.

13. If a current of 2 amperes is used to decompose
water and produces 2.981 g. of oxygen in 5 hr., what
is the electro-chemical equivalent for oxygen ?

14. The current from a battery liberates in a given
time 150 cc. (measured at 0°C. and 760 mm.) of the
mixed gases from acidified wtfter ; if this same current
were passed through a solution of copper sulphate,
what weight of copper would be deposited ?

15. How many coulombs are carried by and will
deposit : 20 g. of silver ; 15 g. of antimony ; 30 g. of
chlorine ; 60 g. of phosphanion (PO4) ?

16. If a current of 15 amperes flows for 1 hour
and 20 minutes, how many coulombs will pass ? How
many ampere-hours will that give ?

17. If the specific resistance of copper is 0.000001629,
what is the resistance of a wire 200 m. long having a
cross section of 2 mm.2?

18. If the specific resistance of German silver is
0.0000209, what is the resistance of 150 m. of wire
having a cross section of 25 mm.2?

142 PROGRESSIVE PROBLEMS IN CHEMISTRY

19. What is the resistance of an electric light carbon
12 inches long by | inch in diameter, when its specific
resistance is 0.07 ?

20. How much zinc will be deposited from zinc sul-
phate by 3 amperes in 10 minutes?

21. How much lead will be deposited by a current
of J an ampere passing for 90 minutes through lead
chloride ?

22. How much chlorine would be liberated by J an
ampere passing through dilute hydrochloric acid for 13
hours ?

23. How much tin will be deposited by 5 amperes
flowing 6 hours through a solution of SnCl2 ?

24. How many amperes will it take to deposit 2^
Ib. of copper from copper sulphate in 10 hours ?

25. What is the minimum voltage necessary to de-
compose water if the heat of combination of 1 g. of
hydrogen with oxygen is 34,180 calories ?

26. If zinc bromide requires 1.65 volts to decompose
it, what is the heat involved by the equivalent weight
of zinc in g. combining with bromine ?

27. If 1 g. of hydrogen, combining with chlorine
in the presence of water, evolves 39,315 calories, -what is
the voltage required for the decomposition of hydro-
chloric acid ?

CHAPTER XII

Analytical Calculations — Strength of Solutions

1. If a solution of hydrochloric acid contained 44
g. of that substance to the L, how many cc. of the solu-
tion would be needed to neutralize 20 cc. of the solution
of sodium hydroxide containing 60 g. to the 1.?

2. What weight of sodium hydroxide will neutral-
ize 100 g. of sulphuric acid ? What weight of potas-
sium hydroxide will neutralize the same ?

3. If in neutralizing a certain amount of nitric acid
with sodium hydroxide, 7.85 cc. of water are formed,
how much nitric acid and how much sodium hydroxide
have been employed ?

4. llow many g. of a 5 % solution of KOH will be
required to neutralize 10 g. of a 10 % solution of
H2S04?

5. If 10 g. of commercial caustic soda, dissolved in
water, required 116.3 g. of a 10 % sulphuric acid to
neutralize the solution, what percentage of pure NaOH
did the substance contain ?

6. If 10 g. of commercial nitric acid were exactly
neutralized by the addition of 58.6 g. of a 10 % solu-
tion of potassium hydroxide, what was the strength of
the acid in pure HNO3 ?

143

144 PROGRESSIVE PROBLEMS IN CHEMISTRY

7. If a solution contained 50 g. of ammonium
hydroxide to the 1., how many cc. of a 10 % solution of
hydrochloric acid will be needed to neutralize 60 cc. of
the ammonium hydroxide solution ?

8. What weight of potassium hydroxide will neu-
tralize 36.2 g. of hydrochloric acid?

9. What weight of sodium hydroxide will neutral-
ize 36.2 g. of hydrochloric acid ?

10. What weight of potassium hydroxide will neu-
tralize 62.7 g. of nitric acid ?

11. What weight of sodium hydroxide will neutral-
ize 62.7 g. of nitric acid ?

12. What weight of potassium hydroxide will neu-
tralize 97.6 g. of sulphuric acid?

13. What weight of sodium hydroxide will neutral-
ize 97.6 g. of sulphuric acid?

14. Suppose we have a molar solution of sodium
hydroxide and a hydrogen chloride solution of unknown
strength. If 50 cc. of the former require 62 cc. of the
latter for neutralization, what is the strength of the
hydrochloric acid solution ?

15. Calculate the weight of sodium hydroxide that
would be neutralized by 50 cc. of a solution of sul-
phuric acid of density 1.23 and containing 31% by
weight of pure acid.

16. What volume of centinormal sulphuric acid solu-
tion would be required to neutralize 0.008 g. of K2CO3 ?

17. HBr solution having a density of 1.515 contains
49.8 % of the gas. How many g. AgNO3 are needed
to precipitate 250 cc. of the solution?

ANALYTICAL CALCULATIONS 145

18. If 75 cc. of HC1 solution neutralize 60 cc. of
NaOH containing 0.003 g. of the alkali per cc., what
was the weight of the acid in 1 cc. of its solution ?

19. A solution of KOH contains 0.02 g. per cc. and 15
cc. of it neutralize 40 cc. of an HC1 solution. Find the
number of g. of HC1 contained in 30 cc. of the solution.

20. How much ammonium hydroxide, sp. gr. 0.88,
and water will have to be mixed to give 200 cc. of
ammonium hydroxide, sp. gr. 0.96?

21. How much nitric acid, sp. gr. 1.42, and water
are needed to make 6 1. of nitric acid, sp. gr. 1.26 ?

22. How much sulphuric acid, sp. gr. 1.7, and how
much water are required to make 400 cc. of sp. gr.
1.18?

23. How much ammonium hydroxide, sp. gr. 0.9,
and water must be mixed to give 4 1. of sp. gr. 0.96 ?

24. Given 2 1. of dilute sulphuric acid, sp. gr. 1.2,
which is to be used up in diluting concentrated sul-
phuric acid, sp. gr. 1.82, to an acid of sp. gr. 1.3, how
much concentrated acid must be added ?

25. A solution of lime water contains 5 g. of lime to
the 1.; how many cc. of N/10 H2SO4 are needed to
precipitate all of the lime from 10 1. of the lime water
solution ?

\ 26. If 300 cc. of a solution of caustic potash contain-
ing 40 g. KOH per 1. are required to neutralize 100 cc.
of sulphuric acid and the same volume of nitric acid,
what is the amount of acid in each solution ?

27. What volume of aqueous hydrochloric acid, con-
taining 36.5 g. HC1 per 1., will be required to neutral-
ize 224.5 g. of Na2CO3, 10 H2O ?

146 PROGRESSIVE PROBLEMS IN CHEMISTRY

28. How many Ib. of 15 % HC1 are needed to neu-
tralize 2000 Ib. of

^ 29. Calculate the weight of crystallized oxalic acid
(C2H2O4, 2 H2O) required for a solution which is to be
made up to 500 cc. in volume at N/2 strength.

30. If 1 1. of a solution of sodium hydroxide contains
35 g. of NaOH, how many g. of nitric acid would be
needed to neutralize exactly 60 cc. of the solution ?

31. How much of the following substances are in
their molar solutions : hydrogen bromide ; potassium
hydroxide ; and potassium iodide ?

32. How much of a tenth-normal hydrochloric acid
solution is necessary to neutralize 3 g. of strontium
hydroxide ?

33. Determine the normality of a sodium dichromate
solution, 50 cc. of which oxidized 3.85 g. of ferrous
ammonium sulphate [FeSO4, (NH4)2SO4,6 H2O] to the
ferric salt.

34. How many g. of 10 % (by weight) solution of
barium chloride are needed to precipitate as barium
sulphate the SO4 in 2 g. of pure magnesium sulphate?

35. How many g. of a 5 % solution of ammonium
oxalate are needed to precipitate completely as calcium
oxalate the lime in 1 g. of calcium carbonate ?

36. How many g. of 15 % solution of NaNH4HPO4
are necessary to precipitate completely the zinc in a
solution containing 0.50 g. of zinc?

37. How many Ib. of 25% sulphuric acid will be
required to neutralize 2000 Ib. of NaHCO3 ; of
CaCO3?

ANALYTICAL CALCULATIONS 147

38. How much iron is present in 10 cc. of ferrous sul-
phate solution, 15 cc. of which required 60 cc. of a solu-
tion of K2O2O7 containing 4.902 g. of the dry salt per 1.?

39. A solution, A, contains 100 g. of KOH to the 1.
A solution, B, contains 100 g. of H2SO4 to the 1. What
volume of solution A is needed to neutralize exactly
25 cc. of S?

40. Calculate the number of g. per 1. to give normal
solutions of NaCl ; ofBad2; of Na3PO4 ; of KOH.

41. Calculate the amounts needed to make 5 1. of N/10
silver nitrate ; 2 1. of N/10 sodium bromide ; 1 1. of
N/20 K2CO3.

42. What weight of iron in the ferrous condition will
100 cc. of N/10 KMnO4 oxidize?

43. 4 g. of pure KMnO4 are dissolved and diluted
to 1 1. ; how many mg. of active oxygen are contained
in each cc. ? What will be its strength in terms of iron ;
of oxalic acid?

44. If 35 g. of FeSO4,7H2O are dissolved and di-
luted to 1 1., how many ing. of active oxygen will each
cc. absorb?

45. How many g. of NaOH must be added to 2 1. of
NaOH solution, the strength of which is 1 cc. = 0.045 g.
H2SO4, to make it a normal solution? How much
water to make it N/2 solution ?

46. How many g. per 1. of KMnO4 will give a so-
lution of such strength that 1 cc. = 1 % of iron when
0.5 g. is taken for analysis?

47. Given a solution of K2Cr2O7, 1 cc. = 0.005 g.
iron, how many g. of KMnO4 per 1. will give a solution
of equal oxidizing strength?

148 PROGRESSIVE PROBLEMS IN CHEMISTRY

48. What volumes of N/2 and of N/10 H2SO4 must
be mixed to give 2 1. of N/5 H2SO4?

49. A solution of hydrochloric acid is desired to be
made exactly normal. If 40 cc. of the solution neu-
tralized 50 cc. of 0.84 N sodium hydroxide solution,
what volume of water must be added per 100 cc. of the
acid solution ?

50. A solution of sodium hydroxide is desired to be
made exactly 0.5 N. If 32 cc. of the solution at hand
were required for the titration of 28 cc. of 0.8 N hy-
drochloric acid, what volume of water must be added per
100 cc. of the alkaline solution ?

51. A solution of sodium carbonate is desired to be
made exactly 0.05 N. If 24 cc. of the solution at hand
neutralized 9.6 cc. of 0.12 N hydrochloric acid solu-
tion, what weight of anhydrous salt, Na2CO3, must be
added per 100 cc. of solution?

52. Calculate the volume of nitric oxide that could
be evolved by the action of copper upon 1000 cc. of a
N/7 nitric acid solution.

53. An excess of iron sulphide was added to 500 cc.
of a solution of sulphuric acid. The volume of hydro-
gen sulphide set free measured 4640 cc. Calculate the
normality of the acid.

54. An excess of sodium sulphite was added to 400
cc. of a solution of hydrochloric acid. The volume of
sulphur dioxide set free measured 5600 cc. Calculate
the normality of the acid.

55. Suppose that 1400 cc. of ammonia were passed
into 500 cc. of N/2 hydrochloric acid solution. Calcu-
late the normality of the hydrochloric acid still present.

ANALYTICAL CALCULATIONS 149

56. If 50 cc. of N/5 hydrochloric acid solution neu-
tralized 40 cc. of an unknown alkaline solution, and 300
cc. of a sulphuric acid solution neutralized 60 cc. of this
same alkaline solution, what is the normality of the sul-
phuric acid?

57. If 200 cc. of a barium hydroxide solution were
required in the titration of 40 cc. of an acid solution,
and 100 cc. of this acid solution exactly neutralized 80
cc. of N/2 alkaline solution, what is the normality of
the barium hydroxide solution ?

58. If 600 cc. of a sulphuric acid solution, when acted
upon by an excess of zinc, evolved 1242 cc. of hydrogen,
what is the normality of the acid ?

59. If 400 cc. of an acid solution, when acted upon
by an excess of zinc, evolved 2430 cc. of hydrogen,
measured over water at +21° C. and 747.5 mm., what
is the normality of the acid?

60. Calculate the normality of a solution of potassium
carbonate, 200 cc. of which, when treated with an excess
of acid, evolved 4502 cc. of carbon dioxide.

61. A slight excess of barium chloride solution was
added to 400 cc. of a solution of sulphuric acid. From
the weight of barium sulphate precipitated, 4.12 g.,
calculate the normality of the acid.

62. If 50 cc. of a solution of hydrogen peroxide were
required to decolorize 400 cc. of N/5 potassium perman-
ganate solution (acidulated), what is the percentage
concentration of the hydrogen peroxide solution?

63. Calculate the weight of a crystallized oxalic acid
required for the reduction of 100 g. of potassium per-
manganate in acid solution. What volume of carbon
dioxide, at standard conditions, would be liberated ?

150 PROGRESSIVE PROBLEMS IN CHEMISTRY

64. If 400 cc. of N/4 potassium hydroxide solution
were required for the neutralization of 600 cc. of an
unknown acid solution, what is the normality of this
acid solution?

65. If 500 cc. of N/10 acid solution were required
for the neutralization of 25 cc. of a solution of sodium
hydroxide, what is the normality of this latter solution?

66. What volume of N/10 acid solution will be
required in the ttitration of 440 cc. of N/4 sodium
hydroxide solution?

67. What volume of N/6 alkaline solution will be re-
quired in the titration of 254 cc. of N/10 acid solution?

68. Calculate the weight of hydrogen chloride pres-
ent in 400 cc. of a hydrochloric acid solution which re-
quired 320 cc. of N/4 alkaline solution for titration.

69. Calculate the weight of sulphuric acid present in
150 cc. of a solution which required 48.1 cc. of 0.78 N
alkali for titration.

70. An excess of silver nitrate solution was added to
350 cc. of a solution of hydrochloric acid. The pre-
cipitate of silver chloride weighed 7.54 g. Calculate
the normality of the acid.

71. The bromine set free by the action of manganese
dioxide upon a hydrobromic acid solution was passed
into a solution of potassium iodide. If 200 cc. of N/10
sodium thiosulphate solution were required for the ti-
tration of the free iodine, what is the weight of the
bromine evolved?

72. Determine the purity of a sample of manganese
dioxide, 2.2 g. of which, with excess of hydrochloric

ANALYTICAL CALCULATIONS 151

acid, set free sufficient chlorine to liberate a quantity of
iodine that required 250 cc. of N/5 sodium thiosulphate
solution for titration.

73. What weight of iron will be required for inter-
action with 400 cc. of N/5 hydrochloric acid?

74. What weight of sodium carbonate will be required
for interaction with 600 cc. of N/8 sulphuric acid?
What volume of carbon dioxide (at standard conditions)
will be evolved ?

75. What weight of sodium hydrogen carbonate,
NaHCO3, will be required for interaction with 600 cc.
of N/8 sulphuric acid? What volume of carbon diox-
ide will be evolved?

76. If 50 cc. of an acidulated potassium permanga-
nate solution were reduced by 2.4 g. of anhydrous
oxalic acid, what is the normality of the permanganate
solution?

77. WThat weight of sulphur dioxide will be oxidized
by 50 g. of potassium permanganate in alkaline solution ?

78. What weight of sodium dichromate must enter
into reaction with a hydrochloric acid solution in order
to liberate 100 g. of chlorine at standard conditions?

79. Determine the normality of a potassium dichro-
mate solution, 25 cc. of which oxidized 1.24 g. of ferrous
sulphate to the ferric salt.

80. What volume of hydrogen sulphide, at 4- 24° C.
and 750 mm. pressure, can be oxidized by 10 g. of
potassium dichromate in acid solution?

81. What weight of potassium dichromate, in acid
solution, will be reduced by 1653.5 cc. of sulphur diox-
ide at + 22° C. and 745 mm. pressure?

152 PROGRESSIVE PROBLEMS IN CHEMISTRY

82. What volume of hydrogen sulphide will be re-
quired for the reduction of 100 g. of ferric chloride,
FeCl3, to the ferrous salt ?

83. What volume of gaseous product may be obtained
in the decomposition of 100 cc. of ammonia by heated
cupric oxide ?

84. What volume of hydrogen sulphide will be re-
quired to reduce 200 cc. of N/10 potassium dichromate
solution (acidulated) ?

85. Calculate the volume of hydrogen sulphide, at
standard conditions, that can be oxidized by 4 g. of
potassium permanganate in acid solution.

86. What weight of sulphur dioxide can be oxidized
by 200 g. of potassium permanganate in acid solu-
tion ?

87. A sample of sodium chromate, weighing 1.6780
g., gave upon analysis 1.4620 g. of sodium sulphate.
What was the percentage of sodium oxide in the
sample ?

88. Calculate the weight of sulphur precipitated in
the reduction of 100 g. of ferric chloride to the ferrous
salt by the action of hydrogen sulphide.

89. What weight of potassium dichromate will 1000
cc. of hydrogen sulphide reduce in acid solution ?

90. Calculate the percentage purity of a quantity of
potassium ferrocyanide, 0.5793 g. of which gave upon
analysis 0.4650 g. of potassium sulphate.

91. What is the percentage of potassium sulphate in
a sample of common alum which analyzed -33.51 % sul-
phur trioxide?

ANALYTICAL CALCULATIONS 153

92. What is the percentage of copper carbonate in a
sample of malachite which on analysis gave 57.1 % copper ?

93. A sample of carnallite (KC1, MgCl2, 6 H2O) on
analysis gave 35.34% chlorine; what is the percentage
of magnesium chloride present?

94. Calculate the percentage purity of a sample of
marble which on analysis gave 39.6% calcium.

95. Calculate the percentage of potassium chloride
in a sample of carnallite (KC1, MgCl2, 6 H2O) which on
being analyzed gave 37.72% chlorine.

96. Calculate the percentage of calcium oxide, CaO,
present in a sample of marble, CaCO3, which on being
analyzed gave 43.8% carbon dioxide.

97. Two g. of impure potassium dicarbonate required,
when titrated cold, in a dilute solution, 6 cc. of N/10
H2SO4; 2 g., when titrated boiling hot, required 18
cc. of normal H2SO4. What are the percentages of
K2CO3andof KHCOo?

A O O

98. What volumes of N/2 and of N/10 H2SO4 must
be mixed to give 2 1. of N/5 H2SO4?

99. A N/10 iodine solution is 2 % too strong. How
many cc. of a N/100 iodine solution must be added to
1 1. to make it right?

100. How much more normal NaOH will it take to
neutralize 1 g. of NaHSO4 than normal KOH to neu-
tralize 1 g. KHSO4?

101. Suppose that 0.2 g. of a nitrogenous organic
compound were heated writh soda lime and the NH3
evolved was caught in 50 cc. N/10 HC1, and that the
excess of HC1 was neutralized by 14 cc. of N/5 NaOH ;
what was the percentage of nitrogen ?

154 PROGRESSIVE PROBLEMS IN CHEMISTRY

102. Iii 1 g. of an antimony alloy the antimony
was determined by N/10 Na2S2O3 and 24.2 cc. were
required ; what is the percentage of antimony ?

103. What amount of type metal must be taken for
analysis so that the burette shall read percentage of
antimony when N/10 Na2S2O3 is used?

104. Five g. of bleaching powder were mixed in a
mortar with water and diluted to 1 1. ; 50 cc. of this
required 30 cc. of N/10 Na3AsO3 solution. What is
the percentage of available chlorine ? Under these con-
ditions, what fraction of normal will read percentage
direct?

105. To 50 cc. of a solution of chlorine an excess of
potassium iodide was added ; the liberated iodine was
then estimated by a N/10 solution of Na2S2O3, starch
being used as an indicator; and 22.5 cc. of Na2S2O3
solution were needed. What is the strength of the
chlorine solution?

106. How much more normal NaOH will it take to
neutralize 1 g. of HC1 than 1 g. of HBr?

107. How many g. per 1. of K2Cr2O7 will give a solu-
tion of such strength that 1 cc. = 1 % of iron when 0.60
g. is taken for analysis ?

108. How many g. of Na2S2O3, 5 H2O per 1. will give
a solution such that 1 cc. =0.5% Cu when 1 g. is
taken for analysis?

109. How much water must be added to 2 1. of
KMnO4, 1 cc. = 0.0065 g. iron, to make it N/10?

110. How much water must be added to 3 1. of
K4Fe(CN)6, 1 cc. = 0.0115 g. zinc, to make it read
percentage directly when 1 g. is taken for analysis?

ANALYTICAL CALCULATIONS 155

111. Given a solution of K2Cr2O7, 1 cc. = 0.0042 g.
Fe, how many g. per 1. of KMnO4 will give a solution
of equal strength?

112. Given a solution of KMnO4, 1 cc. = 0.0056 g.
of iron, what is its strength in terms of manganese
by the Volhard method and by the Ford- Williams
method?

113. What is the strength of N/10 KMnO4 in terms
of H2C2O4; of CaO ; of CaCO8; of CaSO4?

114. What is the strength of N/10 KMnO4 in terms
of P and of MoO3 according to Noyes' method?

115. What is the strength of a N/10 sodium thio-
sulphate solution in terms of iodine ; of copper ?

116. What is the strength of a N/5 iodine solution
in terms of SO2 ; H2SO3; Na2SO3?

117. How many cc. of N/5 Na2S2O3 solution will be
required to react with the iodine liberated by 20 cc. of
a N/10 K2O2O7 solution?

118. How many g. of copper will give, when pre-
cipitated by potassium iodide, sufficient iodine to re-
quire 20 cc. of N/10 SO2 solution? How many for
10 cc. of N/10 Na2S2O3 solution?

119. Five g. of pig iron took 12 cc. of N/100 iodine
solution ; what is the percentage of sulphur ?

120. If 1.5 g. of pig iron took 78 cc. of N/10
KMnO4, what is the percentage of phosphorus?

121. How much NaOH must be added to 1.890 1. of
NaOH solution, the strength of which is 1 cc. = 0.045 g.
H2SO4, to make it normal? How much water to make

it N/2?

156 PROGRESSIVE PROBLEMS IN CHEMISTRY

122. One g. of a rock gave, on analysis : combined
sodium and potassium sulphates, 0.150 g. ; and plati-
num from K2PtCl6, 0.1127 g. What are the percentages
of K2O andNa2O?

123. Which is more economical for neutralizing an
alkali, 60 % HNO3 at 6 cts. per Ib. or 20 % HC1 at 3
cts. per Ib. ?

124. Which is the more economical oxidizing agent,
KNO3 at 5 cts. a Ib. or NaNO3 at 51 cts. a Ib. ?

125. Calculate the number of g. per 1. to give normal
solutions of oxalic acid; of tartaric acid; of acetic
acid ; of citric acid.

126. Calculate the number of g. per 1. to give half
normal solutions of I ; of Na2S2O3, 5 H2O ; of SO2.

127. Calculate the amounts necessary to make 2 1.
of N/10 NaCl and NaBr.

128. Calculate the strength of N/20 KMnO4 to be
used in titrating K4Fe(CN)6.

129. What is the strength of N/10 KMnO4 in terms
of Fe; Fe2O8; Fe3O4; FeSO4, 7H2O?

130. How many g. of oxalic acid in a molar and in
a normal solution?

131. How many cc. of a N/3 solution of AgNO3 will
precipitate 20 cc. of a 10% sodium chloride solution?

132. What weight of As2O3 will be necessary to make
a twice molar and a N/2 solution ?

133. One g. of coal gave 0.2634 g. of BaSO4 by
Eschka's Method; 1 g. of MgO and 0.5 g. of Na2CO3
were used. It was found that both contained sulphur ;

ANALYTICAL CALCULATIONS 157

10 g. of MgO and 5 g. of Na2CO3 (together) gave
0.1654 g. of BaSO4. What is the percentage of sul-
phur in the coal?

134. Suppose that 1 g. of silver is dissolved in nitric
acid and to it is added 0.25 g. of pure dry sodium chlo-
ride. What percentage of the silver remains in solution ?

135. Suppose that 0.25 g. of sodium bromide is
added to a solution of 1 g. of silver; what percent-
age of silver remains in solution?

136. A dolomite contains 98 % of calcium and mag-
nesium carbonates, 2 % of SiO2, and 10 % of MgO ;
what is the percentage of CO2?

137. Calculate the chemical factors for (a) (NH4)2O
from 2NH4C1, PtCl4 ; (5) for K in 2 KC1, PtCl4;
(<?) for P in Mg2P2O7 ; (cT) for Fe2O3 from Fe3O4.

138. If 0.5 g. of platinum remains after the ignition
of the precipitate of the double salt, 2 NH4C1, PtCl4,
derived from 1 g. of an ammonium compound, calculate
the percentage of NH3 in the latter. 2 NH4C1, PtCl4 =
2NH3+2HCl + 2Cl2 + Pt.

139. What weight of Mn3O4 corresponds to 1 g. of
Mn2P207?

140. How many cc. of aqueous ammonia (sp. gr. ==
0.96), containing 9.90% of NH3 by weight, will be re-
quired to precipitate the iron as Fe(OH)3 from 1 g.
of (NH4)2SO4, FeSO4, 6 H2O ?

141. How many cc. of HNO3 (sp. gr. = 1.135), con-
taining 20 % of HNO3 by weight, are required to oxi-
dize the iron in 1 g. of FeSO4, (NH4)2SO4, 6 H^O, in
the presence of sulphuric acid? 6 FeSO4 + 2 HNO3 +
3 H2S04 = 3 Fe2(S04)3 + 2 NO + 4 H2O. .

158 PROGRESSIVE PROBLEMS IN CHEMISTRY

142. The ignited precipitate of Fe2O3 -f- A12O3 from
1.5 g. of a silicate weighs 0.4069 g. ; this mixture loses
0.0200 g. when ignited in hydrogen. What is the per-
centage of Fe2O3 and A12O3 in the sample? Fe2O3 -f
3 H2 = 2 Fe + 3 H2O.

143. How many cc. of " magnesia mixture " (64 g.
MgCl2 per 1.) will be required to precipitate the arsenic
from 0.2 g. As2S3 after oxidation to arsenic acid?

H3 As04 + MgCl2 + 3 NH4OH = MgNH4 AsO4 +
2 NH4C1 + 3 H20.

144. How many cc. of sulphuric acid (sp. gr. = 1.75),
containing 81 % H2SO4 by weight, are necessary to re-
place the nitric acid in the nitrates formed from 5 g.
of a brass containing 65 % Cu, 34.5 % Zn, and 0.5 % Pb?

145. If 5.23 g. of brass yield 0.0345 g. of PbSO4,
and subsequently 0.0031 g. of PbO2 on electrolysis of
the filtrate, what is the percentage of Pb in the brass?

146. If in the analysis of a brass containing 65%
copper, an error is made in weighing a 5 g. portion, by
which 0.001 g. too much is weighed out, what would
be the percentage of copper as determined? If the
same error is made in weighing 0.2 g. of apatite con-
taining 40 % P2^5' wnat will be the apparent percent-
age? What will be the percentage error in each
case?

147. If the dry cupric sulphide from 0.82 g. of brass
loses 0.1345 g. on ignition in hydrogen, what is the
percentage of copper in the brass? 2 CuS = Cu2S + S.

148. If 1.5 g. of glass yield 0.38 g. KC1 + NaCl,
from which 0.646 g. 2 KC1, PtCl4 is obtained, what is
the percentage of Na2O in the glass?

ANALYTICAL CALCULATIONS 159

149. How many cc. of an ammonium oxalate solu-
tion [(NH4)2C2O4, H2O] (40 g. per 1.) are required
to precipitate the calcium as oxalate from 1 g. of apa-
tite [Ca3(PO4)2, CaCl2]? How many cc. of "mag-
nesia mixture" (containing 64 g. MgCl2 per 1.) are
necessary to combine with the phosphoric acid in the
same weight of apatite ?

150. If a calcium oxalate precipitate (which is con-
taminated by silica) from 0.83 g. of dolomite is ignited
under such conditions that the decomposition products
may be passed through Ba(OH)2 solution, and the
resulting precipitate of barium carbonate is found, on
drying, to weigh 0.9500 g., what is the percentage of
CaO in the sample?

151. How many cc. of a potassium tetroxalate solu-
tion (KHC2O4, C2H2O4, 2 H2O), containing 50 g. per
1., would be required to precipitate the calcium from
1 g. of a sample of dolomite yielding 2% Fe2O3, 10%
MgO, and 45% CO2, assuming the iron, magnesium,
and calcium to be present wholly as carbonates, the
iron as ferrous carbonate?

152. A mixture of BaO and CaO weighing 0.2438 g.
yields 0.4876 g. of mixed sulphates. What is the
weight of each oxide in the original mixture?

153. Calculate the percentage of pure Na2CO3 in an
impure sample from the following data : crucible +
SiO2 = 20.0697 g. ; crucible + SiO2 + Na2CO3 (im-
pure) = 20.3264 g. ; crucible + SiO2 (excess) +Na,2SiO3
(after fusion) = 20.2239 g. Assume the reaction to be
Na2CO3 + Si02 = Na2Si03 + CO2.

154. A sample of pyrite weighing 0.5 g. yields 1.6 g.
BaSO4. Calculate the per cent of FeS2 in the sample.

160 PROGRESSIVE PROBLEMS IN CHEMISTRY

155. How much crude cream of tartar should be
taken for an analysis in order that the number of cc.
of N/2 NaOH solution required to react with it shall
represent directly the percentage of KHC4H4O6 ? How
much oxalic acid in order that each cc. of N/10 KMnO4
may represent 1 % C2H2O4, 2 H2O?

KHC4H4O6 + NaOH = KNaC4H4O6 + H2O.

156. What weight of potassium ferrocyanide [K4Fe
(CN)6, 3 H2O] should a normal solution contain for
use as a reducing agent?

10 K4Fe(CN)6, 3 H2O +2 KMnO4 + 8 H2SO4 =
10 K3Fe(CN)6 + 6 K2SO4 + 2 MnSO4 + 8 H2O +
30 H20.

157. Calculate the percentage of carbon dioxide in a
sample of calcium carbonate from the following data :

Total volume N/2 HC1 = 35 cc. ; total volume N/10
NaOH = 15 cc. ; weight carbonate = 1.00 g.

158. Calculate the weight of KHC2O4, C2H2O4,
2 H2O necessary for a 1. of normal solution, (a) as a
standard acid solution, (5) as a reducing agent.

KHC2O4, C2H2O4, 2 H2O + 2 MnO2 + 3 H2SO4 =
2 MnSO4 + KHSO4 + 4 CO2 + 4 H2O + 2 H2O.

159. Given the following data, calculate the percent-
age purity of the oxalic acid :

Standardization: weight CaCO3= 1.050 g. ; HC1
solution used = 45 cc. ; NaOH solution used =4.8 cc. ;
1 cc. NaOH solution = 1.042 cc. HC1 solution.

Analysis: weight oxalic acid = 1.500 g. ; NaOH
solution used = 42.5 cc. ; HC1 solution used = 0.5 cc.

160. Given the following data, calculate the per-
centage purity of the cream of tartar (KHC4H4O6) :

ANALYTICAL CALCULATIONS 161

Weight of substance = 2.500 g. ; NaOH solution
used = 25.51 cc. ; H2SO4 solution used = 0.5 cc. ; 1 cc.
H2SO4 solution = 1.02 cc. NaOH solution ; 1 cc. NaOH
solution = 0.0255 g. CaCO3.

161. If 10 cc. of a sulphuric acid solution yield
0.1220 g. BaSO4, how much must the solution be
diluted for an exactly N/10 solution?

162. If 1 cc. of a potassium bichromate solution will
oxidize 0.0066 g. of iron, to what volume must 100 cc.
of the solution be diluted to make a N/100 solution ?

163. Calculate the percentage of iron (Fe) in a
sample of limonite from the following data :

Weight of limonite = 0.55 g. ; K2Cr2O7 solution
used = 51.1 cc. ; 1 cc. K2O2O7 solution = 0.0058 g. Fe ;
FeSO4 solution used = 5 cc. ; 5 cc. of FeSO4 solution
contains 0.008 g. FeO.

164. A sample of iron wire is dissolved, out of con-
tact with air, in 30 cc. of HC1, of which 1 cc. = 0.95 cc.
N/2 HC1. The iron requires 40 cc. of N/10 K2Cr2O7
for oxidation. What excess of HC1 was used over that
required for solution ?

165. How much stannous chloride by weight will be
required to reduce the iron from 0.5 g. magnetite
(FeO, Fe2O3), dissolved out of contact with air ?

166. How many cc. of HC1 (sp. gr. =1.12) are
required to dissolve 0.55 g. limonite (2 Fe2O3, 3 H2O),
assuming the only impurity to be 1.5 % quartz ?

167. If 0.75 g. of a silicate yields 0.4 g. Fe2O3 +
A12O3, and the iron present requires 20 cc. K2Cr2O7 solu-
tion [1 cc. = 0.0784 g. FeSO4(NH4)2SO4, 6 H2O], cal-
culate the percentage of FeO and A12O3 in the sample.

162 PROGRESSIVE PROBLEMS IN CHEMISTRY

168. What weight of iron wire containing 99.85 % Fe
will react with the chromium from 0.5 g. of chromite
(FeO, Cr2O3) ?

169. Calculate the value of a permanganate solution,
of which 1 cc. = 0.008 g. of Fe, in terms of MoO3-

Mn2O7 + 10 FeO = 5 Fe2O3 + 2 MiiO ;
7 Mn2O7 + Mo24O37 = 24 MoO3 + 14 MnO.

170. Given the following data, calculate the per-
centage of iron in the limonite :

Weight of limonite = 0.55 g. ; KMnO4 solution used
= 30 cc. ; 1 cc. KMnO4 solution = 0.0084 g. C2H2O4,
2 H20.

171. The calcium oxalate precipitate from 0.5 g. of
marble, when treated with sulphuric acid, liberates
sufficient oxalic acid to reduce 43 cc. of permanganate
solution (1 cc. = 0.0115 g. Fe). Calculate the per-
centage of calcium in the marble.

172. If 1 cc. of KMnO4 solution will oxidize 0.008 g.
iron, calculate the equivalent of the same solution
in terms of hydrogen peroxide, and also the volume of
oxygen which will be evolved by each cc. of the per-
manganate solution during the reaction, assuming that
1 cc. of oxygen weighs 0.00143 g. under the existing
conditions.

5 H202 + 2 KMn04 + 3 H2SO4 = K2SO4 + 2 MnSO4 +
5O2+5H2O.

173. Given the following data, calculate the per-
centage of MnO2 in the pyrolusite :

Weight of pyrolusite = 0.48 g. ; weight of FeSO4,
(NH4)2SO4, 6 H2O = 4.3501 g. ; K2Cr2O7 solution used
= 10 cc. ; 1 cc, K2Cr2O7 solution = 0.005 g. Fe.

ANALYTICAL CALCULATIONS 163

174. Given the following data, calculate the per-
centage of MnO2 in the pyrolusite :

Weight of pyrolusite = 0.48 g. ; weight of iodine
liberated from KI = 1.296 g.

175. If 1 cc. iodine solution is equivalent in oxidiz-
ing power to 0.00149 g. of KBrO3, to what volume
must 100 cc. be diluted to make a N/20 solution ?

176. Calculate the percentage purity of the sample
of potassium dichromate from the following data :

Weight of sample = 0.1237 g. ; Na2S2O3 solution
used = 25 cc. ; 1 cc. Na2S2O3 solution = 1.004 cc. iodine
solution ; 1 cc. iodine solution = 0.004975 g. As2O3.
K2Cr2O7 + 6 KI + 7 H2SO4 = 4 K2SO4 + Cr2(SO4)3 +
3I2 + 7H20.

177. Calculate the percentage purity of a sample of
potassium iodate from the following data :

Weight of sample = 0.25 g. ; Na2S2O3 solution used
= 50 cc. ; 1 cc. Na2S2O3 solution = 0.015 g. I.

178. If 1 cc. of an iodine solution has the same
oxidizing power as 0.0034 g. of KIO3, calculate its
value in terms of antimony.

CHAPTER XIII

Review — Systematic and Miscellaneous
SYSTEMATIC REVIEW

1. A pressure of 1000 Ib. per in.2 is how many Kg.
per mm.2?

2. When the mercury (sp. gr. = 13.59) barometer
stands at 76 cm., how high will one of glycerine (sp.
gr. = 1.27) stand?

3. When the mercury barometer stands at 760 mm.,
how high would one of hydrogen sulphate (sp. gr. =
1.83) stand?

4. When the barometer stands at 31 in., what is it
in mm.?

5. When the barometer stands at 755 mm., what is
it in in.?

6. When the pressure of the air is 750 mm. of mer-
cury (sp. gr. = 13.59), what is it (0) in feet of water ;
(6) in Ib. per in.2?

7. If 200 cc. of oxygen are measured off over water
at +14° C. and 756 mm., what does the dry normal gas
measure ?

8. How much MnO2 is required to make 10 1. of
oxygen ?

164

SYSTEMATIC REVIEW 165

9. What weight and volume of oxygen at +15° C.
is obtained on passing CO2 over 1 Kg. of calcium plum-
bate heated to redness and then through slaked lime?
Ca2Pb( )4 + 2 C02 = 2 CaCOg + PbO + O.

10. If 481 g. of BaO2 are heated, what volume of
oxygen at + 17° C. and 800 mm. is evolved?

11. What would be the volume of the liquefied gas
if the density of it is 0.89?

12. In an experiment the CuO lost 59.789 g. and
67.282 g. of water was formed. Calculate the atomic
weight of oxygen.

13. What volume is occupied by 1 g. of liquid hydro-
gen (sp. gr. = 0.07) ? If the boiling point is - 238.5° C.,
what is it in F.°?

14. A balloon holds 64 m.3 of hydrogen ; how many
Kg. does the gas weigh?

15. How many 1. of hydrogen at -f 10° C. and 770
mm. are obtained on passing 2 g. of steam over red-hot
iron?

16. What is the mass of 1 1. of hydrogen measured
over water at + 50° C. and 790 mm. ?

17. What volume is occupied by 100 g. of steam
measured at +300° C.?

18. What is the volume of 1000 g. of (a) sea water
(sp. gr. = 1.026); (6) ice (sp. gr. = 0.92)?

19. A block of ice (sp. gr. = 0.92) weighs 280 Kg.;
find its volume.

20. If the density of ice is 0.92, what volume will
1000 cc. of water at + 4° C. occupy when frozen?

21. An iceberg floats in sea water with 30,000 m.3
above the sea ; what is the total volume of the berg ?

166 PROGRESSIVE PROBLEMS IN CHEMISTRY

22. If 100 g. of gypsum are heated, what volume of
steam at + 300° C. is given off?

23. If 88.88 parts of oxygen unite with 11.11 parts
of hydrogen, and the equivalent of oxygen be 100, what
is the equivalent of hydrogen?

24. If 500 cc. of hydrogen at +39° C. are exploded
with 500 cc. of oxygen under a pressure of 332.5 mm.
what volume of which gas is left?

25. How much water must be electrolyzed to give a
1. of gas at + 15° C. and 740 mm.?

26. Find the density of steam at + 300° C. referred
to air at 0° C. A Ib. of dry steam at + 374° F. occu-
pies how many ft.3?

27. How many g. does a ft.3 of aqueous vapor meas-
ure at + 212° F. and 30 in. of mercury weigh?

28. What do 100 1. of nitrogen weigh?

29. When 100 g.' of Pb(NO3)2 were heated, they
were found by Svanberg to leave 67.4016 g. of PbO.
If O = 100 and Pb = 1294, what is the atomic weight
of nitrogen ?

30. What volume is occupied by 10,000 g. of HNO3
(sp.gr. =1.53)?

31. What is the least quantity of H2SO4 which can
be used to decompose 500 g. of KNO3?

32. How much KNO3 and what volume of H2SO4 (sp.
gr. =1.84) must be distilled together to form a 1. of
HNO3 (sp. gr. = 1.53) ?

33. How many oz. of AgNO3 are formed by the
action of HNO3 (sp. gr. = 1.4) upon 1000 g. of Ag?

34. How much NH4NO3 is required to make 40 1. of
N20?

SYSTEMATIC REVIEW 167

35. What volume of hydrogen is required to combine
with the oxygen contained in 10 g. of nitrous oxide?

36. What volume of NO at + 13° C. is obtained on
dissolving 25 g. of Cu in HNO3?

37. What volume of oxygen is required to convert
10 g. of NO in presence of water into HNO3?

2NO + H20 + 30 = 2HN03.

38. How many g. of NH3 can be obtained from 2140
g. of NH4C1?

39. How many g. of NH3 are obtained on passing
3 g. of NO, mixed with excess of H, over hot spongy
Pt?

2 NO + 10 H = 2 NH3 + 2 H2O.

40. If 2 g. of potassium are heated in NH3, how
much potassamide and what volume of H at + 15° C.
are formed?

41. If 2 1. of nitrosyl chloride at + 15° C. are passed
over warm AgNO3, how much N2O5 is formed?

NO2C1 + AgNO3 = AgCl + N2O5.

42. If 100 1. of air are passed over red-hot Cu, how
much does the Cu increase in mass?

43. If 20 cc. of air are mixed with 30 cc. of H
and exploded, what volumes of what gases are left?

44. What is the difference in mass between 10 1. of
air at + 15° C. and 10 1. of N under 775.62 mm. ?

45. A man inhales 18 ft.3 of air per hour. How
many Ib. of O does he require in 24 hr. ?

46. What is the mass of 500 m.3 of air at + 21° C. ?

168 PROGRESSIVE PROBLEMS IN CHEMISTRY

47. An inch of rainfall is how many tons of water per
acre?

48. How much moist iron can be oxidized by 1000 1.
of air at + 13° C. ?

49. How much S can be burned in 20 1. of air at + 26°
C.?

50. What volume of air at + 21° C. must be passed
over 100 g. of Cu to convert it into CuO ?

51. How much Mg can be burned in a globe contain-
ing 5 1. of air at +21° C. and 744 mm. ?

52. A cubic mile of air at 760 mm. and -f- 30° C. is
saturated with water vapor. How many tons of rain
will fall if the temperature sinks to 0° C. ?

53. In one of Lord Rayleigh's experiments, 7925 cc.
of air left 65 cc. of argon ; what is the percentage by
volume of argon in the atmosphere?

54. The specific heat of graphite is 0.202; what is
its probable atomic weight?

55. If 4427 million ft.3 of coal are piled into a cube,
find the length of each edge in m.

56. Find the formula of a substance containing:

0,20%; 0,26.6%; 8,53.3%.

57. What volume of air is required to burn a Kg. of
carbon ?

58. If 15.2 1. of methane at -f 17° C. and 870 mm. are
required, how much dry sodium acetate must be used?

59. If 25 cc. of ethene are exploded with 100 cc. of
O, what volume of CO2 is formed and of O is left?

60. What volume of cyanogen at + 16° C. is given
off on heating 5 g. of Hg(CN)2?

SYSTEMATIC REVIEW 169

61. Find the mass of 295 cc. of camphor (C10H16O)
vapor at + 210° C.

62. In Meyer's third method, 0.12 g. of dibromamy-
lene gave 13.1 cc. of air at + 17° C. and 758 mm.
Find the density of the vapor.

63. How many g. of MnO2 are required to make
40 1. of Cl at + 37° C. ?

64. What volume of Cl at + 12° C. and 750 mm.
can be obtained from 1170 g. of salt?

65. If 10 g. of K2Cr2O7 are heated with HC1, what
volume of Cl at + 30° C. and 740 mm. is given off?

K2Cr2O7 + 14 HC1 = 7 H2O + 2 KC1 + 2 CrCl3 + 3 C12.

66. What volume of Cl will diffuse under the same
conditions as 10 cc. of N ?

67. When 1 g. of bleaching powder was boiled with
CuO, it gave 80 cc. of O at + 7° C. and 800 mm.
Find the percentage of real bleaching powder in the
sample.

68. What is the mass of 1 1. of chloroform vapor
measured at + 200° C. ?

69. How many cc. does a Ib. of Br (sp. gr. = 3.19)
occupy ?

70. How much P and what volume of Br is required
to make 1 1. of HBr ?

P + 3 Br + 3 H2O = H3PO4 + 3 HBr.

71. Br vapor is 2.8 times as heavy as air ; what is its
molecular weight?

72. If 10 g. of KBrO3 are heated, what volume of
oxygen measured at + 13° C. is given off ?

73. A spherical glass bulb contains 10 g. of liquid
Br (sp. gr. = 3.19) ; what must the internal radius be ?

170 PROGRESSIVE PROBLEMS IN CHEMISTRY

74. How much FeCl3 is required to obtain iodine
from 100 tons of kelp, each ton of which contains 4.07
Kg. of iodine ?

2 Nal + 2 FeCl8 = 2 NaCl + 2 FeCl2 + I2.

75. How many times is solid iodine (sp. gr. = 4.94)
as heavy as an equal volume of its vapor measured at
+ 350° C. ?

76. How much iodine is there in a 1. of a solution
(sp. gr. = 1.7) containing 52% of HI?

77. How much iodine and KC1O3 are required to
make 1 Kg. of hydrogen iodate ?

10 KC1O3 + 12 I + 6 H2O = 10 KC1 + 12 HIO3.

78. If 8 g. of silver iodate are heated, what volume
of oxygen at + 18° C. and 720 mm. is evolved?

79. What volume of HF at + 39° C. can be obtained
from 50 g. of NaF?

80. Find the mass of 10 1. of HF at + 30° C. and
740 mm.

81. What volume is occupied by 1000 g. of (a)
common sulphur (sp. gr. = 2.05), (6) plastic sulphur
(sp. gr. = 1.95)?

82. What volume is occupied by 19.2 g. of SO2?

83. If 16 cc. of H diffuse in 100 sec., what volume
of SO2 will diffuse under the same conditions?

84. How much iodine is needed to oxidize 1 g. of
" hypo," and how much sodium tetrathionate is formed ?

2 Na2S203, 5 H20 + T2 = 2 Nal + 10 H2O + Na2S4O6.

85. SO3 is passed over 187 g. of BaO in a heated
tube ; how much BaSO4 is formed?

SYSTEMATIC REVIEW 171

86. How many Kg. of H2SO4(sp. gr. =1.84) will
a tank 1 m. x 2 m. x 3 m. hold ?

87. If 100 g. of Pb form 146.45 g. of PbSO4, what
is the molecular weight of H2SO4 ?

88. If 20 g. of S are heated in H, what volume of
H2S at + 30° C. is formed?

89. If 390 g. of Sb2S3 are dissolved in hot HC1, what
volume of H2S at + 30° C. is given off ?

90. How many g. of S are there in 600 ec. of H2S ?

91. What volume of H2S will diffuse under the same
conditions as 10 cc. of oxygen ?

92. How much PbS and HgS can be thrown down
by 500 cc. of H2S at + 14° C. ?

93. What volume of CS2 (sp. gr. =1.26) can be
made by the action of a Kg. of S upon hot charcoal?

94. What is the mass of 4 1. of carbon oxysulphide
(COS) at + 30°C. ?

95. To make 1000 Kg. of H2SO4, how much pyrite is
needed ? What volume of air at + 15° C. and of
steam at + 300° C. are required ?

2 FeS2 + 4 H20 + 15 O = Fe2O3 + 4 H2SO4.

96. What volume of CS2 (sp. gr. =1.26) must be
burned to give 101. of SO2 at + 15° C. and 750 mm.?

97. Boron trichloride is 4.07 times as heavy as air;
what is its molecular weight ?

98. How many g. do 200 cc. of BC13 at + 97° C. and
720 mm. weigh?

99. If 90 g. of CaF2 are heated with B2O3 and
H2SO4, what volume of BF3 at + 15° C. is formed ?

3 CaF2 + B203 + 3 H2SO4 = 3 CaSO4 + 3 H2O + 2 BF3.

172 PROGRESSIVE PROBLEMS IN CHEMISTRY

100. How much Si can be obtained from 119 g. of
K2SiF6 ? K2SiF6 + 4 K = 6 KF + Si. i

101. How much silica is formed on burning 2 1. of
SiH4?

102. What volume of Cl. at + 26° C. and mass of 0
are required to make 100 g. of SiCl4 ?

Si02 + 2 C + 2 C12 = 2 CO + SiCl4.

103. How much does a 1. of SiCl4 at + 200°C.
weigh?

104. Find the mass in g. of a sphere of quartz
(sp. gr. = 2.65) 1 dm. in diameter.

105. How much bone ash containing 87% of
Ca3(PO4)2 is required to make 200 Kg. of superphos-
phate of lime?

Ca3(P04)2 + 2 H2S04 = 2 CaSO4 + CaH4(PO4)2.

106. If 100 1. of yellow (sp. gr. = 1.83) are con-
verted into red (sp. gr. = 2.16) phosphorus, what is
the volume of the latter variety ?

107. What is the mass of 1.234 1. of P vapor (P4)
at + 500° C. ?

108. If 1 g. of P, when burned, gives 2.29 g. of P2O5,
what is the atomic weight of P?

109. Find the formula of a substance containing :
Ca, 38.72%; P, 20%; O, 41.28%.

110. If 20 g. of hydrogen metaphosphate are boiled
with water, how much orthophosphate is formed ?

HP03 + H20 = H3P04.

111. If 5 g. of phosphorus are boiled with baryta
water, what volume of PH3 at + 15° C. is given off ?

2 P4 + 3 Ba(OH)2 + 6 H2O = 3 Ba (PH2O2)2 + 2 PH3.

SYSTEMATIC REVIEW 173

112. What volume of PHg will diffuse under the
same conditions as 100 cc. of hydrogen ?

113. What volume of Cl at + 20° C. must be passed
into 1 Kg. of melted P to convert it into PC18 ?

114. How much P is contained in 4.3 1. of PH3 meas-
ured at + 22° C. and 730 mm. ?

115. How many g. do 2 1. of As4 vapor weigh ?

lie. If 743 cc. of gas are heated from +47° C. to
-f- 83° C., what is the new volume ?

117. What volume do 486 cc. of gas under a pressure
of 760 mm. occupy under the pressure of 3 ft. of
mercury ?

118. If 1000 cc. of air at -31.2° R. are heated to
+ 172.4° F., what is the new volume?

119. If 546 cc. of gas at + 17° C. and 760 mm. are
cooled to 0° C., the pressure being decreased to 600
mm., what is the new volume ?

120. If 1234 cc. of normal gas are cooled to — 52° C.,
the pressure being decreased to 617 mm., what is the
new volume ?

121. A few drops of water at + 15° C. are passed
up into a barometer standing at 30 in. How high does
the mercury stand ?

122. If 100 g. pf Sb gave 124.8 g. of Sb2O4, and if
O = 100, what is the atomic weight of Sb ?

123. Bi melts at + 264° C ; what temperature is
this on the F. and R. scales ?

124. Schneider found that 54.969 g. of Bi formed
61.311 g. of the trioxide ; what is the atomic weight
of Bi ?

174 PROGRESSIVE PROBLEMS IN CHEMISTRY

125. What volume is occupied by 10 g. of trimethyl-
stibine Sb(CH3)3 at + 300° C.?

126. What is the mass of a sphere of Bi (sp. gr. = 9.9)
2 mm. in diameter ?

127. Find the volume of 100 g. of (a) Pt (sp. gr.
= 21.5); (6) Au (sp. gr. =19.3); (c) Pb (sp. gr.
= 11.4); (d) Li (sp.gr. = 0.59).

128. What length of wire 2 mm. in diameter can be
drawn from 1 dm.3 of metal ?

129. How much platinum black is obtained on boil-
ing 40 g. of platinic chloride with grape sugar and
sodium carbonate ?

PtCl4 + 2 Na2C03 = 4 NaCl + 2 CO2 + O2 + Pt.

130. If 900 g. of Au (sp. gr. = 19.3) are fused with
100 g. of Ag (sp. gr. = 10.5), what is the density of
the alloy?

131. If 5 g. of K2O4 are boiled with water, what vol-
ume of O at + 100° C. is evolved ?

K204 + H20 = 2 KOH +30.

132. If 2 g. of hydroxylamine are heated with KOH,
what volumes of N and of NH3 at 4- 21° C. are formed ?

3 NOH3 = N2 + NH3 + 3 H2O.

133. How much SrO is obtained on heating 1000 g.
ofSr(N03)2?

134. One g. of CaSO4 will form how much BaSO4 ?

135. How much Al is set free on passing '7. 339 1. of
the vapor of A1C13 at + 546° C. over heated Na ?

2 A1C13 + 6 Na = 6 NaCl + A12.

136. How much sulphide is formed on heating 5 g.
of Al in S vapor ?

SYSTEMATIC REVIEW 175

137. If 20 g. of cryolite are heated with H2SO4, what
volume of HF at + 20° C. is given off ?

2 Na8AlF6 + 6 H2SO4 = 3 Na2SO4 + A12(SO4)3 + 12 HF.

138. If 4 g. of dolomite, when strongly heated, gave
937.4 cc. of CO2, what is the percentage of Ca and
MgCO3 in the dolomite ?

(CaMg)C03 = (CaMg)O + CO2.

139. What volume of N at -h 20° C. and 780 mm.
will combine with 50 g. of Mg ?

140. How much zinc white can be made from 1000 g.
of Zn and what volume of air is required ?

141. Brass consists of 2 parts of Cu alloyed with
1 part of Zn ; find the approximate formula for it.

142. If 100 g. of sodium manganate are heated in
steam, what volume of oxygen at -h 13° C. is set free ?

Na2MnO4 + H2O = 2 NaOH + MnO2 + O.

143. During the solution of 1 g. of iron, 389.74 cc.
of H at + 14° C. and 820 mm. were evolved ; find the
equivalent of iron.

144. According to Berzelius, 1.586 g. of Fe form
2.265 g. ferric oxide; what is the atomic weight of
iron ?

145. What volume of CO at + 17° C. is set free on
heating 10 g. of diferroheptacarbonyl to + 80° C. ?

Fe2(CO)7 = Fe + Fe(CO)5 + 2 CO.

146. How much S precipitates on passing 1.7 1. of
H2S at + 17° C. through a solution of FeCl3?

2 FeCl3 + H2S = 2 FeCL + 2 HC1 + S.

176 PROGRESSIVE PROBLEMS IN CHEMISTRY

147. How much Fe is converted from a ferrous to
a ferric salt by 1 g. of potassium (a) permanganate ;
(5) dichromate ?

10 FeSO4 + 2 KMnO4 + 8 H2SO4 =

5 Fe2(SO4)3 + K2SO4 + MnSO4 + 8 H2O ;
6 FeSO4 + K2Cr2O7 + 7 H2SO4 =

3 Fe2(S04)3 + K2S04 + Cr2(SO4)3 + 7 H2O.

148. If 3 g. of KMnO4 and K2Cr2O7 are each dis-
solved in 1 1. of water, to how much Fe is 1 cc. of each
solution equivalent ?

149. What volume of CO at + 1200° C. is set free in
reducing 764 g. of nickelous oxide ?

NiO + C = Ni + CO.

150. How much HgO is required to precipitate 20 g.
of Ni as NiO ?

NiCl2 + HgO = HgCl2 + NiO.

151. What is the formula of a substance containing :
Ni, 31.15%; H, 3.18 %; N, 14.84%; S, 16.95%;
O, 33.88%? .

152. What volume of H at + 15° C. is required to
reduce 100 g. of Co2O3?

153. If 100 g. of Hg2CrO4 are heated, how much
Cr2O3 is formed and what volume of O is given off?

2 Hg2Cr04 = 4 Hg + Cr2O3 + 5 O.

154. According to Siewert, 36.865 parts of CrCl3
give 100 parts AgCl ; find the atomic weight of chro-
mium.

155. How much (NH4)2Cr2O7 can be made from
1000 g. of K2Cr207 ?

K2Cr207 + H2S04 = K2S04 + H2O + 2 CrO3 ;
2 Cr03 + 2 NH3 + H2O = (NH4)2Cr2O7.

SYSTEMATIC REVIEW 177

156. According to Berlin, 100 g. of Pb(NO3)2 gave
97.576 g. of PbCrO4; find the atomic weight of chro-
mium.

157. What volume of SO2 at + 15° C. and 780 mm.
is required to reduce 47 g. of K2Cr2O7?

K2Cr207 + 3S02 + H2S04 = Cr2(SO4)3 + KaSO4+ H2O.

158. How many times is the vapor of chromyl dichlo-
ride (CrO2Cl2) as heavy as air ?

159. If 17 g. of Sn were dissolved in NaOH, what
volume of H at -f- 15° C. was evolved ?

Sn + 2 NaOH + H2O = Na2SnO3 + 2 H2.

160. What volume of HC1 at + 60° C. is required to
convert 50 g. of Sn into stannous chloride?

161. What volume of Cl at + 26° C. is absorbed in
converting 1000 g. of Sn into the tetrachloride?

162. What volume of H2S at + 26° C. is required to
throw down the Sn from a solution of 110 g. of " tin
salts"?

SnCl2, 2 H20 + H2S = SnS + 2 HC1 + 2 H2O.

163. If 9 g. of Sn are dissolved in aqua regia, what
volume of H2S at + 15° C. and 770 mm. is required to
precipitate them?

164. If 4 g. of Sn are heated in 200 cc. of H2S at
+ 10° C. and 744 mm., how much does the Sn increase
in mass ?

165. What volume of air is required to convert 37.1
Kg. of Pb into litharge?

166. How much silica must be fused with 1000 g. of
PbO to form lead silicate ?

178 PROGRESSIVE PROBLEMS IN CHEMISTRY

167. What volume of O at + 13° C. is absorbed in
forming 1000 g. of red lead?

168. According to Dumas, 100 g. of minium when
heated give 2.4 g. of O; find its formula.

169. Find the percentage composition of realgar,
orpiment, and arsenic pentasulphide.

170. What volume of H2S at + 21° C. is required to
precipitate the As from a solution of 100 g. of As2O3?

171. The specific heat of As is 0.0814 and 96.15
parts of As combine with 3.85 parts of H; find the
atomic weight of the element.

172. How much Sb is there in 1020 Kg. of the tri-
sulphide ?

173. What volume is occupied by 100 g. of (a) As
(sp. gr. = 5.8) ; (6) Sb (sp. gr. = 6.8) ; <» Bi (sp. gr. =
9.9)?

174. How much lead dioxide can be made from 20 g.
of Pb(N03)2?

Pb(N03)2 + CaOCl2 + H20 = 2 HC1 + Ca(NO3)2 + PbO2.

175. Find the formula of Cassel yellow, which con-
tains: Pb, 90.05%; Cl, 3.86%; and O, 6.09%.

176. PbI2 is soluble in 190 times its mass of hot water.
How much KI and Pb(NO3)2 must be dissolved in
250 cc. of water that the precipitate may redissolve on
boiling ?

177. According to Stas, 100 g. of Pb form 195. 9703 g.
of Pb(NO3)2; what is the atomic weight of Pb?

178. A substance contains of lead monoxide 76.69%
and of chromium trioxide 23.31% ; find its formula.

SYSTEMATIC REVIEW 179

179. What volume of CO2 at -f 26° C. is evolved on
dissolving 487 g. of white lead in hydrogen nitrate?

Pb(OH)2, 2 PbC03 + 6 HN03 =
4H20 + 3Pb(N03)2 + 2C02.

180. What volume is occupied by the vapor of 4 g.
plumbic ethide, Pb(C2H5)4, measured at + 300° C. and
740 mm.?

181. If 100 g. of CuSO4 are warmed with KOH and
grape sugar, how much cuprous oxide precipitates?

2 CuSO4, 5 H2O + 4 KOH =
2 K2SO4 + 12 H2O + O + Cu2O.

182. What volume of H at + 100° C. and 746 mm.
is given off on dissolving 3 g. of cuprous hydride in
HC1?

Cu2H2 + 2 HC1 = Cu2Cl2 + 2 H2.

183. If 8000 g. of cinnabar are roasted, how much
Hg and what volume of SO2 at + 13° C. are formed?

184. Hg vapor is 6.976 times as heavy as air; find
its density referred to H.

185. When 1 Kg of Hg at -f 100° C. is mixed with
1 Kg of water at -f 10° C., the temperature of the
mixture was found to be + 13° C.; what is the specific
heat of Hg?

186. Find the formula of a cadmium amalgam which
contains : Hg, 78.26 %, and Cd, 21.74%.

187. Excess of Hg is heated in 10 1. of air measured
at + 14° C. ; how much HgO is formed ?

188. The vapor of Hg2Cl2 is 8.21 times as heavy as
air; what is its apparent molecular weight?

189. How many g. do 500 cc. of the vapor of corro-
sive sublimate at -h 350° C. weigh?

180 PROGRESSIVE PROBLEMS IN CHEMISTRY

190. How much Fe and Hg are required to reduce
48 Ib. of AgCl?

191. Melted Ag dissolves 22 times its volume of
oxygen at 0° C. What volume of O at + 13° C. would
be given off by 1 Kg. of Ag (sp. gr. = 10.5) on cool-
ing?

192. According to Stas, 53.1958 g. of Ag form
92.6042 g. of AgBr; what is the atomic weight of
silver ?

193. What volume of H2S at + 27° C. and 570 mm.
is required to precipitate the Ag from 100 g. of silver
metaphosphate ?

2 AgP08 + H2S = Ag2S + 2 HP03.

194. How much FeSO4 is required to precipitate
100 g. of Au?

6 FeS04, 7 H20 + 2 AuCl3 =
4 Fe2(SO4)3 + 42 H2O + 2 FeCl3 + 2 Au.

195. How much magnesia is required to throw down
10 g. of auric oxide ?

2 AuCl3 + 3 MgO = 3 MgCl2 + Au2O3.

196. What volume of O is given off on heating
4.412 g. of Au2O3?

197. Prat has described an oxide of gold containing
7.7% of oxygen; find its formula.

198. How much aurous bromide can be made from
2 g. of Au2O ?

199. If 50 g. of auric chloride are heated to + 170° C.,
how much aurous chloride and what volume of Cl
measured at + 21° C. are formed?

AuCL = AuCl + CL.

SYSTEMATIC REVIEW 181

200. A solution of 10 g. of AuCl3 is mixed with hy-
drogen oxalate ; how much Au precipitates and what
volume of CO2 at + 13° C. is given off?

2 AuCl3 + 3 H2C2O4 = 2 Au + 6 HC1 + 6 CO2.

201. How much spongy platinum is left on heating
100 g. (NH4)2Pt018?

202. How much PtCl4 is obtained on dissolving 500 g.
of Pt in aqua regia?

203. How much platinous hydrate is formed on di-
gesting 200 g. of platinous chloride with KOH?

PtCl2 + 2 KOH = 2 KC1 + Pt(OH)2.

204. According to Berzelius, 10 g. of Pt form
24.735 g. of K2PtCl6; find the atomic weight of
platinum.

MISCELLANEOUS REVIEW

205. How much CaO and how much coke are
needed to produce 100 Ib. of CaC2?

206. How much chrome-alum could be made from
10 Kg. of chromite?

207. What weight of chrome-yellow would be formed
if a solution containing 430 g. of K2CrO4 were precipi-
tated with lead acetate ?

208. What weight of KMnO4 could be prepared from
10 Kg. of an ore containing 62 % pyrolusite ?

209. Find the percentage composition of nitric acid.
How many g. of each component in 150 g. of nitric
acid?

210. Find the percentage composition of H2SO4.
How many g. of HC1 can be formed by the action of
490 g. of H2SO4onNaCl?

182 PROGRESSIVE PROBLEMS IN CHEMISTRY

211. Find the percentage composition of H2S. How
many g. of H2S can be made by the action of 146 g. of
HC1 on ferrous sulphide?

212. A mixture of 30 cc. of air and 40 cc. of hy-
drogen is introduced into a eudiometer tube and the
mixture ignited by an electric spark. The gas remain-
ing in the tube after the explosion measures 51.1 cc.
What per cent, by volume of oxygen is contained in
the air used, assuming that the gases are all measured
at the same temperature?

213. A candle of paraffine (C, 85 % ; H, 15 % ) loses
90 g. in weight by burning ; find the weights and
volumes of the products of combustion and of oxygen
used.

214. What weight of phosphorus would be needed to
combine with 700 cc. of oxygen to form phosphorus
pentoxide?

215. If 1 g. of hydrogen and 1 g. of oxygen are
mixed and the mixture is ignited, what weight of water
will be formed and what volume of gas will remain
uncombined ?

216. What weight of oxygen will unite to form water
with a volume of hydrogen that measures 1250 cc. at
740mm. and +18°C.?

N 217. A certain analysis gives 42.1% of carbon, 7.1 %
of hydrogen, 56.2% of oxygen, (a) Find a formula
for the compound. (5) It being hexabasic, give the
true formula. (<?) All the hydrogen can be replaced by
a metal. To what class of compounds does it belong?
218. Reduce the following to the Fahrenheit scale :
(a) +35°C. ; (5) + 89° C. ; <V) -40° C. ; (d) -50°
C. ; 0) + 104° C.

SYSTEMATIC REVIEW 183

219. If a given weight of gas occupies 1.1 1. at 0° C.
and 380 mm., what volume should it occupy at + 273°
C. and 760 mm. ?

220. Reduce the following to ft.3 or in.3 : (a) 1.5 1. ;
(6) 760 cc. ; (c) 7 m.3 ; (d) 85 dm.3 ; <» 900 cc. ;
(/) 1.2 cc.

221. If water absorbs 1000 times its volume of am-
monia, how many g. of ammonium chloride will furnish
enough gas for 2 1. of water ?

222. How many g. of coin silver, which is T9^ pure,
will make 50 g. of bromide of silver for photog-
raphy ?

223. Prove that the phosphorus molecule has 4 atoms.

224. A m.3 of carbon monoxide burns in air. (a) Find
the number of cc. of carbon dioxide which will form at
N.T.P. (5) Find approximately the number of ft.3

225. A cube of sulphur (sp. gr. = 2) is 2| cm. on a
side ; how much SO2, by weight and by volume, will
form on burning it ?

226. By using 100 tons of FeS2 there were obtained
136.3 tons of H2SO4. If there were no waste, what per
cent, of sulphur does the pyrite carry ? What per cent,
does pure FeS2 carry ?

227. A mixture of | hydrogen by volume and J arsine,
5 1. in all, is burned, (a) What weight of water is
formed ? (£) What volume would the arsenic occupy
at -f 273° C. if it could be set free as a gas ?

228. H2SO4 has sp. gr. =1.84; what volume of sul-
phur dioxide at + 200° C. and 700 mm. will be given by
30 cc. of it reduced by copper ?

184 PROGRESSIVE PROBLEMS IN CHEMISTRY

229. What volume of hydrogen is required to combine
with the oxygen in 12 g. of nitrous oxide ?

230. Water will absorb 1050 times its volume of am-
monia gas ; how many g. of ammonium chloride will
be required to furnish the gas sufficient to saturate 500
cc. of water ?

231. If 10 1. of hydrogen diffuse through a certain
apparatus in a certain time, what volume of hydrogen
phosphide will diffuse under similar conditions ?

232. Compute the vapor density (a) of ozone from
the atomic weight of oxygen and the fact of there being

3 atoms in the molecule of ozone ; (5) of arsenic with

4 atoms per molecule ; (<?) of zinc, which has 1 atom per
molecule.

233. A block of lead (sp. gr. = 11.4) 5x2x2 cm.
is dissolved by HNO3 ; how much NO by volume ought
to be liberated ?

234. How much CaCO3 by weight should be formed
by introducing into lime water the carbon dioxide formed
in burning 500 cc. of liquid ether having sp. gr. =
0.72?

235. How much phosphorus by weight can be burned
in 5 1. of nitrogen monoxide ?

236. How much H2S by volume will be formed by the
action on FeS of 1 1. of HC1 solution which has sp.
gr. = 1.2 and contains 43% HC1 gas ?

237. A substance analyzed gives 20% water, 26.66%
carbon, 53.13% oxygen; find its formula.

238. How much chlorine in a 1. of water, 20 cc. of
which will precipitate all the silver in 0.02 g. of silver
nitrate ?

SYSTEMATIC REVIEW 185

239. If 2 Kg. of coal produce in burning 6 Kg. of CO2
and 900 g. of water, what percentage of carbon and of
hydrogen does the coal contain ?

240. One g. of an aqueous solution of hydrogen
chloride (sp. gr. = 1.20) contains how many cc. of
hydrogen chloride ?

241. How many Kg. in 3 m.3 of sulphuric acid (sp.

242. What volume would be occupied by 2 cc. of sul-
phuric ether (sp. gr. = 0.72) if it were vaporized at
+ 270° C. and 750 mm. ?

243. Reduce the following to C.° : (a) + 38° F. ;
(6) + 120° F. ; (<0 -64° F. ; (d) - 30° F. ; (e) 0° F. ;

244. If equal volumes of hydrogen and oxygen are
mixed in a closed space at a temperature above the
boiling point of water, and the mixture is exploded,
what will be the pressure of the products compared
with the original pressure at the same temperature ?

245. When 37.4 g. of nickel oxide were heated in a
current of hydrogen they lost in weight 8.000 g. The
specific heat of nickel is 0.109. What information do
these data give concerning the atomic weight of nickel ?

246. Write the equations representing the volume
relations, (a) when carbon monoxide burns in oxygen ;
(5) when ammonia gas is decomposed into its elements.
Give the relative numbers of molecules taking part in
each reaction .

247. What volume is occupied by 80 g. of ammonia
(a) at N.T.P.; (b) at +273° C. and pressure of 2
atmospheres ?

186 PROGRESSIVE PROBLEMS IN CHEMISTRY

248. How much ammonium chloride must be heated
with lime to make 50 1. of ammonia at N.T.P. ?

249. Write equations for (a) the action which takes
place on boiling water hardened by carbonate of mag-
nesium in solution ; (6) the preparation of peroxide of
hydrogen; (<?) the action of carbonic acid on barium
hydrate.

250. How much zinc sulphate can be made from
20 Ib. of zinc ?

251. If 3 1. of a gas consisting of carbon and oxygen
weigh 3.78 g., what is the formula of the gas ?

252. Compare the diffusibilities of these gases, carry-
ing the answer to one decimal place : (a) N2O and CO ;
(5) Br and Cl; <» N and NH3; (d) NO and H;
<Y) CO and CO2 ; (/) CH4 and HC1; (#) C2H6O and
(C2H5)2O; (A) H2S and CS2; (i) H and H2S.

253. A gas, A, diffuses 3.5 times faster than B\ if
the molecular weight of A is 4, what is that of B ?

254. Two gases, A and J5, diffuse approximately at
6.1:4.1; if A has a molecular weight of 34, what
should be that of B ?

255. If 3 1. of nitrous oxide weigh 5.94 g., what is
its vapor density ?

256. What is the weight of 1239 1. of phosphorus
vapor at +21° C. ?

257. A manufacturer prepares phosphorus from 169
tons of bones, containing 55 % of calcium phosphate ;
how much phosphorus should he obtain and how much
oil of vitriol ought he to use ?

258. How much chlorine by volume can be got from
10 g. of NaCl?

SYSTEMATIC REVIEW 187

259. If 5 1. of turpentine vapor are burned in air,
(«) what are the products ; (b) what is the volume of
the compound of carbon formed at 0° C. and 760 mm. ?

260. Excess of carbon is thrown into 100 g. of fused
niter; what volume of N and of CO2 is evolved?

4 KNO3 + 5 C = 2 K2CO3 + 4 N + 3 CO2

261. If the density of marsh gas is 0.55 and its per-
centage composition is carbon, 74.95, and hydrogen,
25.05, prove that the atomic weight of carbon is not
more than 12.

262. Prove that the molecule of oxygen has at least

2 atoms.

263. How many cc. of liquid water are contained in
a rectangular piece of gypsum (sp. gr. = 2.3) which is

3 cm. x 5 cm. x 7 cm. ? How much SO2 is contained
in it?

264. When 7 cc. of sulphur vapor and 5 cc. of oxygen
combine, so far as possible, to form SO2, how many
cc. of SO2 are formed and how much of either factor is
left?

265. A cube of crystallized NaCO3x 10 H2O (sp. gr. =
1.45) is 6 cm. on a side, (#) What volume, as a
liquid, would the water of crystallization occupy ?
(£) What volume would the gaseous CO2 obtainable
from the salt at N.T.P. occupy ?

266. (a) How much sulphur by weight is required
to make 1000 g. of H2SO4? (5) If the sp. gr. of
H2SO4 is 1.84, how many 1. would the acid occupy ?

267. How much SO2 by volume could be obtained by
acting with H2SO4 on a plate of copper (sp. gr. = 8.85)
which is 5 cm. x 8 cm. x 10 cm. ?

188 PROGRESSIVE PROBLEMS IN CHEMISTRY

268. A certain volume of gas at 740 mm. and -J- 30° C.
weighs 5 g. ; what would an equal volume of the same
gas weigh at 760 mm. and 0° C. ?

269. Of two gases, A and B, A diffuses twice as rap-
idly as B ; compare their molecular weights.

270. Uranium is the metal having the greatest
atomic weight, 238.5; compute its specific heat from
the atomic heat.

271. GASEOUS COMPOUNDS ANALYSES SP. GR.

HX H:X=1:3 0.557

OX O:X = 8:3 1.529

HNX H:N:X = 2:28:24 0.948

In the above table we have gaseous compounds of an
element X. The analyses of the compounds are given,
also the sp. gr., air being unity. Air is 14.4 as heavy
as hydrogen. What is the atomic weight of the ele-
ment X ? Give reasons.

272. How many 1. of HC1 at + 273° C. and 760 mm.
could be obtained by treating with H2SO4 a cube of
rock salt (sp. gr. = 2.13) which measures 5.5 cm. on
a side ?

273. How many 1. of hydrogen would be needed to
combine with all the oxygen in 50 g. of mercuric oxide ?

274. If 4 1. of hydrogen diffuse through an apparatus
in 10 minutes, and 1 1. of oxygen in an equal time under
similar conditions, what is the density of oxygen?

275. (a) How many cc. of oxygen at +33° C. are
needed to burn 175 cc. of benzene vapor? (5) What
would be formed? (<?) What weight of CO2 ?

276. I wish to make 30 g. of potassium chloride;
how much potassium chlorate ought I to take ?

SYSTEMATIC REVIEW 189

277. Assume that in burning all 2240 Ib. of a certain
soft coal in gas retorts, 6 Ib. of ammonia gas are liber-
ated and collected in the ammoriiacal liquor ; that 5 % is
lost in the transportation and working of the liquor ;
that it is made into ammonium sulphate. How much
dry sulphate of ammonium will it yield, and how much
pure sulphuric acid will be used in the operation,
assuming no waste of acid ?

278. What volume at + 20° C. and under a pressure
of 2 atmospheres will 100 1. of sulphur dioxide, meas-
ured at 0°C. and under a pressure of 1 atmosphere,
occupy ? What weight of sulphur is necessary to pro-
duce this amount of sulphur dioxide ?

279. If the combustion of 1 g. of sulphur to sulphur
dioxide develops 2220 calories, what is the heat of com-
bustion of sulphur ?

280. Calculate the number of m.3 of air at + 20° C.
needed for one Kg. of coal, the composition of which is :
carbon, 76.81%; hydrogen, 5.14%; oxygen, 7.90%;
nitrogen, 1.62 % ; sulphur, 1.13 % ; water, 1.70 % ; ash,
6.65 %. Assume the factor for excess as 3.

281. If 1 volume of water at -f 20° C. absorb 650
volumes of NH3, what weight of ammonia will be
taken up by 1 1. of water at the same temperature ?

282. What weight of NaOH will neutralize 100 1. of
HC1?

283. At 0° C. 1 volume of water will absorb 500
times its own volume of HC1. How much will 500 g.
of water at 0° increase in weight by absorbing all the
HClitcan?

284. What weight of HC1 can be obtained from 25 g.
of salt ? How much Na2SO4 is formed ?

190 PROGRESSIVE PROBLEMS IN CHEMISTRY

285. A silver coin containing 8 % of copper weighs
2.43 g. If the coin is dissolved in HNO3, how many
g. of NaCl will be needed to precipitate all the silver
as AgCl ?

In the above, what weight of iron will be required to
reduce the AgCl to metallic silver and what will be
the weight of the silver obtained ?

286. How many tons of pure hematite would be
needed for the production of 100 tons of iron in the
blast furnace, assuming that 2.3% of the iron in the
ore passes into slag ?

287. How much coke would be needed to reduce 50
tons of pure hematite ?

288. An ore contains 36.4 % of " Ruby Copper "
(Cu2O). With what weight of charcoal must 10 tons
be heated to reduce all the Cu2O to metallic copper ?

(Cu2O + C = 2 Cu + CO.) ' Find weight of copper.

289. How much potassium hydroxide will react with
20 g. of chlorine, in the formation of potassium chlorate ?

290. How much potassium hydroxide must be used
to obtain 5.0 g. of potassium chlorate ?

291. How much sodium hydroxide will neutralize
10 g. of nitric acid ?

292. How much sulphuric acid will be neutralized by
20 g. of potassium hydroxide ?

293. How much hydrochloric acid will neutralize 25
g. of sodium hydroxide ?

294. If 40 cc. of a solution of potassium hydroxide
are neutralized by 25 cc. of a solution of hydrochloric
acid containing 0.001 g. of the acid per cc., what weight
of the hydroxide is contained in 10 cc. of its solution ?

SYSTEMATIC REVIEW 191

295. If 50 cc. of a solution of nitric acid are neutral-
ized by 70 cc. of a solution of sodium hydroxide con-
taining 0.004 g. of the alkali per cc., what weight of
the acid is contained in | 1. of its solution ?

296. If 25 cc. of a solution of potassium hydroxide
are neutralized by 45 cc. of a solution of sulphuric
acid containing 0.002 g. of the acid per cc., what
weight of the hydroxide is contained in one 1. of its
solution ?

297. How much ammonia gas can be obtained -from
40 g. of ammonium chloride ?

298. How much ammonia is necessary for the produc-
tion of 20 g. of ammonium nitrate ?

299. What weight of nitrogen will appear when 100
g. of chlorine are taken up in the decomposition of
ammonia ?

300. How much nitrous anhydride is obtainable from
60 g. of potassium nitrite ?

301. Calculate the weight of a 1. of nitric oxide
under standard conditions.

302. What is the weight of a 1. of hydrocyanide under
standard conditions ?

303. A 1. of gas under 700 mm. pressure at + 40° C.
weighs 1.307 g. ; what is its molecular weight?

304. Five 1. of a gas under 2 atmospheres pressure at
4- 50° C. weigh 10.6 g. ; what is the molecular weight
of the gas ?

305. Seven 1. of sulphur dioxide, at + 90° C., are
produced by burning 12 g. of sulphur in oxygen ; what
is the pressure of the gas ?

192 PROGRESSIVE PROBLEMS IN CHEMISTRY

306. The oxygen obtained from 100 g. of potassium
chlorate occupies 30 1. under the pressure of 70 cm. of
mercury ; what is the temperature of the gas ?

307. What volume of carbon dioxide at + 20° C. and
740 mm. pressure would be produced by the explosion
of 10 g. of gunpowder (supposing gunpowder to be
2 KNO3 + 3 C + S) according to the equation

2 KN03 + 3 C + S = 3 C02 + N2 + K2S ?

308. What volume of nitrous oxide, at -f- 30° C. and
800 mm. pressure, is obtainable from 100 g. of ammo-
nium nitrate ?

309. How many 1. of hydrogen will result from the
electrolysis of 50 g. of water, when the gas is collected
over mercury, the level within the tube being 90 mm.
above that without, and the temperature and barometric
pressure being + 23° C. and 745 mm. respectively ?

310. How many g. of water may be obtained by burn-
ing a quantity of hydrogen occupying 400 1. at 4- 50° C.
and 600 mm. pressure ?

311. Ten 1. of a compound weigh 19.8 g. If T8T of it
is oxygen and the remainder carbon, find its formula.

312. What will be the volume of a gas at 760 mm.
pressure and + 60° C., which is 2 1. at 380 mm. and
+ 90° C. ?

313. If 70 cc. of nitrous oxide should break up, what
would be the weight of each constituent ?

314. A mixture of lead sulphate and barium sulphate
weighed 4 g. and analysis of the mixture gave 1.62 g.
of SO4 ; what are the weights of lead sulphate and barium
sulphate present in the mixture ?

SYSTEMATIC REVIEW 193

315. A mixture of the acid sulphates of sodium and
potassium weighs 0.5 g., and analysis of the mixture
shows 0.395 g. of SO4; what weights of sodium and of
potassium are contained in the mixture ?

316. A mixture of acid and neutral potassium car-
bonates weighs 1 g., and contains 0.4 g. of carbon diox-
ide ; what is the weight of each carbonate ?

317. A sample of pure dolomite weighs 1 g. and
yields 0.48 g. of carbon dioxide ; what weights of cal-
cium oxide and of magnesium oxide does it contain ?

318. Which is the more economical oxidizing agent,
potassium nitrate at 5 cts. a Ib. or sodium nitrate at
5| cts. a Ib. ?

319. Which is more economical for neutralizing an
alkali, 60 % nitric acid at 6 cts. a Ib. or 30 % HC1 at
3 cts. a Ib. ?

320. Which is the most economical for making car-
bon dioxide, sodium dicarbonate at 3 cts. a Ib., sodium
carbonate crystallized at 2J cts. a Ib., or calcium car-
bonate (marble) at 1 ct. a Ib. ?

321. Which is the more economical for the prepara-
tion of anhydrous ammonia, ammonium sulphate at 8
cts. a Ib. or ammonium chloride at 11 cts. a Ib. ?

322. Which is the more economical oxidizing agent,
potassium chlorate at 8 cts. a Ib. or sodium chlorate
at 10 cts. a Ib. ?

323. Given two iron ores, one a lake ore containing
62 °/0 of iron and the other an ore containing 45 % of
iron, how much of each must be used to give 100 tons
of mixture containing 53 % of iron ?

194 PROGRESSIVE PROBLEMS IN CHEMISTRY

324. Suppose we wish to form 100 tons of a mixture
of ores containing 10 % of copper, and we have at our
disposal lots containing 7 % and 18 % respectively ;
how many tons of each must be taken ?

325. Given two iron ores, one containing 0.52% of
phosphorus and the other 0.14%, how much of each
must be mixed to give 20 tons (2240 Ib. to the ton)
containing 0.22% of phosphorus?

326. Given lead ores containing 60 % and 25 % of
lead respectively, how many Ibs. of each must be
mixed to give 5000 Ib. containing 45 % of lead ?

327. Suppose we have 10 tons of coal containing
2.5% of sulphur. We have also supplies of coal con-
taining 0.80% and 1.10% of sulphur. How much of
each shall we add to the 10 tons to make 20 tons con-
taining 1.80 % of sulphur ?

328. Coal contains about 2 % of nitrogen. Assuming
that 75 % of this amount escapes as ammonia on distilla-
tion, calculate the amount of coal required to furnish
the sal-ammoniac needed to produce 10 Kg. of NH4OH.

329. If 100 volumes of Manchester cannel gas con-
tained 4.98 volumes of olefines which yielded on com-
bustion 13.93 volumes of carbon dioxide, what were
the volumes of C2H4 and C4H8 contained in the gas ?

330. One ft.3 of hydriodic acid is decomposed by
an excess of bromine ; how many ft.3 of hydrobromic
acid are formed ?

331. If 5 1. of chlorine are mixed with 5 1. of carbon
monoxide, what volume of phosgene gas is produced,
and how much hydrochloric acid and carbon dioxide
would be produced by the decomposition of this gas
with water ?

SYSTEMATIC REVIEW 195

332. How many g. of water at 0° C. would be frozen
by the removal of the heat required to evaporate 50 g.
of liquid ammonia ?

333. Find the density of the gas the formula of
which is N2O5. Find the weight of a 1. of phosphine.

334. Calculate the volume of hydrochloric acid solu-
tion (density 1.10 and 20.9% pure acid) that is re-
quired to make 500 g. of barium chloride from the
carbonate.

335. What volume of air containing 21 % of oxygen
by volume is required to burn 248 g. of phosphorus ?

336. If 25.82 1. of nitric oxide diffuse through a
certain apparatus in 50 minutes, what volume of hydro-
gen will diffuse under the same conditions ?

337. How many g. of sodium chloride dissolved in a
1. of water would be required to elevate the boiling
point of the solution 0.52° C. ?

338. How much white lead should be obtained theo-
retically from 65 Kg. of lead ?

339. How much air would be necessary to change
6 1. of nitrogen dioxide into the trioxide? (Consider
all measurements at 0° C. and 760 mm.)

340. Suppose we had a bar of aluminum weighing
1800 g., how many cc. of water would it displace ?

341. How much sodium nitrate (98% pure) would
have to be present in a fertilizer that contained 4 % of
nitrogen, assuming that all the nitrogen came from the
nitrate ?

342. How many g. of KI dissolved in a 1. of water
are necessary to lower the freezing point of the solu-
tion + 1.86° C. ?

196 PROGRESSIVE PROBLEMS IN CHEMISTRY

343. Find the density of the gas having the formula
N2.

344. Find the weight of a 1. of hydrogen chloride.

345. One 1. of gas weighs 0.09 g. ; find its molecular
weight. What is this gas ?

346. How much sodium would be necessary, assum-
ing exact proportions, to produce 3 Kg. of aluminum
from 2 A1C13, 2 NaCl ?

347. How many cc. of a solution of potassium per-
manganate which contains 40 g. to the 1. would be
necessary to oxidize 0.5 g. of iron from the ferrous to
the ferric condition ?

348. How much aluminum should we theoretically
obtain from an ore containing 90 % of bauxite ?

349. If 500 g. of sulphur containing 17% impurities
are burned in air, what weight of oxygen is needed ?

350. If 2 g. of gunpowder produce 600 cc. of gas
at 0° C., what is the volume at + 2500° C. ?

351. What weight of carbon is contained in (V) 1 1.
CO ; (5)1 1. CO2; (<?) 1 1. C2H2; (d) 1 1. CH4; («) 1 1.
C2H4?

352. The velocity of diffusion of nitrogen is 1.0143;
how many atoms of nitrogen are there in a molecule ?

353. The velocity of diffusion of oxygen is 0.9487;
how many atoms of oxygen are there in a molecule ?

354. If 25 cc. of dilute H2SO4 required 2.44 g.
BaCl2, 2 H2O for complete precipitation, what percent-
age of water was present in the dilute acid ?

355. How much H2SO4 is needed to decompose 27 g.
of common salt ?

SYSTEMATIC REVIEW 197

356. What is the weight of 40 1. of NH3 at 0° C. and
760 mm. ? If 40 1. of HC1 are mixed with it, what is
the weight of the residue ?

357. If 20 g. oxalic acid are warmed with H2SO4, how
much CaCO3 can be produced by passing the products
through lime water and what volume of gas passes
over?

358. If 130 g. of NH3 burn, what are the weights of the
products of combustion ?

359. Calculate the effect of adding 2 volumes of a
saturated (3.90 molar) solution of potassium chloride
to a saturated (0.52 molar) solution of potassium
chlorate. Assume that 1.95 molar KC1 is 0.71 ionized.

360. The sum of the readings of the same temperature
on the F. and C. scale is 172 ; what is the reading on
each ?

361. A sample of carbon containing 85 % of carbon
and 3% of hydrogen is burned; what volume of air
containing 21 % of oxygen is used ?

362. What weight and volume of air contain 1 g.
of nitrogen ?

363. What volume of chlorine acting on NH3 will
give 10 1. of nitrogen ?

364. Give the sum and the difference in weight of 20
1. of nitrogen and 20 1. of air.

365. To give 6 1. of PH3, how much zinc must be
treated with sulphuric acid to give the required amount
of hydrogen ?

366. If 13 g. As2S3 have been thrown down in a
solution by the passage of H2S, what volume of H2S
at + 16° C. and 761 mm. was used ?

198 PROGRESSIVE PROBLEMS IN CHEMISTRY

367. How much As2O3 corresponds to 12 g. of As2S3 ?

368. If 1.311 g. of As2S3 were obtained as a result of
the analysis of the stomach in a poison case, how much
paris green was swallowed ?

369. To produce 20 g. P2O5, how much (a) phos-
phorus and how much (b) PH3 must be burned?

370. One g. of hydrogen is passed over 100 g. of
CuO ; find weight of H2O and the loss of the CuO.

371. How many oz. of gold per ton are represented
by 40 parts to the million? What would be the value
of such ore, rating gold at $20.00 per oz.?

372. From the following data calculate the weight in
Kg. of each constituent of the air in a room 12' 0" x
15' 0" x 9' 0" : — Composition of the air by volume :
nitrogen, 77.35%; oxygen, 20.77%; argon, 0.94%;
water vapor, 0.90% ; carbon dioxide, 0.03% ; a 1. of air
of above composition weighing 1.29 g.

373. From the following data calculate the weight in
Kg. of each constituent of the air in a room 12' x 15' x
9' : assume water vapor = 0.90 % and carbon dioxide =
0.03%.

374. The sp. gr. of zinc is 7.2. A block of it
2 cm. x 3 cm. x 4 cm. is dissolved in HC1. How much
hydrogen (a) by weight and (5) by volume is evolved?

375. A block of charcoal -^ pure is 5 cm. x 6 cm.
X 7 cm., and has sp. gr. = 1.5 ; how much CO2 by vol-
ume ought to form in burning it?

376. If PbCO3 has a sp. gr. = 6.46, how much CO2
by volume could be obtained from a cubical mass of it,
7 cm. on a side?

SYSTEMATIC REVIEW 199

377. At 60 cents per oz., what is the value of the
silver in ^ Ib. of silver nitrate ?

378. If a skeleton weighs 21 Ib. and is 56 %
Ca3(PO4)2, how many matches can be tipped with the
phosphorus it contains, if 1 Ib. of phosphorus serves to
tip a million matches ?

379. How much iron is present in a solution which

M

requires 47 cc. of a — solution of KMnO4 to produce a

pink color?

380. If 5.24 g. coke on burning give 17.54 g. of
CO2, what is the percentage of carbon in the coke?

381. If 2 g. were lost by heating a piece of Iceland
spar, what weight and volume of CO2 were produced at
+ 13°C. and 700mm.?

382. How much HF by volume is needed to reduce
the weight of a piece of glass 3 g.?

383. If 300 tons carbon (87 % pure) are burned in
air, how much oxygen is needed ? What volume of gas
is produced at - 6° C. and 721 mm.?

384. What volume of gas is given by 1 g. of "black
lead" on complete combustion at standard conditions?

385. If 12.1764 1. of nitrogen diffuse through a po-
rous plate in the time that it takes 9.7044 1. of CO2 to
do so, what is the density of CO2 compared with air?

386. If 300 1. of nitrogen dioxide diffuse through a
porous plate in 1 hour, what volume of silicon tetra-
fluoride will diffuse through in the same time ?

387. The sp. gr. of bromine is 3.18 ; find the volume
of vapor given off when measured at + 90° C.

200 PROGRESSIVE PROBLEMS IN CHEMISTRY

388. How much H2SO4 will 20 g. of SO3 dissolved in
water yield?

389. If 60 1. of nitrogen tetroxide diffuse through a
porous, plate in 1 hour, what volume of chlorine tet-
roxide will diffuse through in the same time ?

390. How many g. of MnO2 and how many cc. of a
solution of HC1 (containing 20 % of HC1) are necessary
to evolve 1.86 1. of chlorine at 0° C. and 760 mm. ?

391. How much water will be formed by the action
of (a) copper upon 98 g. of hot hydrogen sulphate ;
(5) hydrogen fluoride upon 60 g. of silicon dioxide ?

392. If 120 cc. of a mixture of CO and hydrogen are
exploded with oxygjen, 40 cc. of gas remain, of which
30 cc. are absorbed by KOH solution ; find the compo-
sition of the mixture.

393. If 20 1. of hydrogen diffuse through a porous
plate in 10 minutes, determine the volume of nitrogen
monoxide that will diffuse through in the same time.

394. If x cc. of a gas are measured at + 15° C. and
755 mm., the normal volume is 1:000 cc. ; find the
numerical value of x.

395. The sp. gr. of ammonia gas under standard con-
ditions is 0.591 ; what is its sp. gr. when the barometer
stands at 750 mm. ?

396. The sp. gr. of chlorine is 2.45 under standard
conditions ; what is the barometric height when the
sp. gr. is 2.40 ?

397. One 1. of hydrogen under standard conditions
weighs 0.0896 g. ; what is the weight of 1 1. when
the barometer stands at 740 mm. ?

SYSTEMATIC REVIEW 201

398. One 1. of air under standard conditions weighs
1.29 g. ; what is the weight of 2.5 1. when the barome-
ter stands at 755 mm. ?

399. If 72 g. of an aqueous solution of H2O2, when
decomposed, give 2.79 1. of oxygen at 0° C. and 760
mm., what is the percentage of H2O2 in the solution?

400. Sea water contains 0.00475 g. CaCO3 per 1. ;
what quantity of sea water would be needed to prepare
56 g. of lime ?

401. If 21 g. of borax are heated to constant weight,
what is the loss and what per cent, of the whole ?

402. Silicon fluoride was passed into cold water and
27 g. of SiO2 were produced ; how much of the gas
was used ?

403. A gas is composed of 92.3 % of C and 7.7 % H ;
how many atoms of hydrogen are united to 2 atoms
of carbon ?

404. If hydrogen sulphide is diluted with 10 times
its volume of hydrogen, what volume of it, estimated as
pure gas, will be dissolved by 20 volumes of alcohol at
0° C. and 760 mm. ?

405. A Dumas bulb full of air weighs 13.3125 g.
After being filled with the vapor of carbon tetrachloride
at 100° C., it weighs 13.7969 g. Filled with water, it
weighs 141.3 g. The barometric reading is 755 mm.
What is the vapor density referred to air at 0° C. and
760 mm. ?

406. What volume of air is required to oxidize one
formula-weight of zinc sulphide to ZnO and SO2, and
what volume of sulphur dioxide is produced ? Is the

202 PROGRESSIVE PROBLEMS IN CHEMISTRY

product more or less diluted with nitrogen than when
pure sulphur is burned, and by how much ?

407. How much chlorine is needed to displace bromine
in a solution of NaBr containing 16 g. ?

408. How many g. of sulphur in 3 1. of SO2; 6 g.
of S08; 10 1. of H2S; 16 g. of K2SO4?

409. If 8.132 1. of CO diffuse through an open-
ing in the time that .it takes 10.7 1. of marsh gas to
pass through, what is the density of marsh gas compared
with that of air ?

410. If 3.804 1. of oxygen diffuse through a certain
opening in the time that it takes 4.066 1. of CO to pass
through, what is the density of CO compared with that
of air ?

411. Determine the density of oxygen compared with
air, given that 5.706 1. of oxygen diffuse through a hole
in the time it takes 22.68 1. of hydrogen to pass through.

412. What volume of HI weighs the same as J 1. of
oxygen at 0° C. and 760 mm. ?

413. A solution of common salt required 6 g. of
AgNO3 to precipitate it completely as AgCl ; how much
sodium was present ?

414. If 150 tons of H2SO4 are made from 110 tons of
a crude native sulphur, find the percentage of sulphur
in the native product.

415. One ton of iron pyrites containing 50 % sulphur
will make how much H2SO4 ?

416. A fire extinguisher contains 2 Ib. of NaHCO3;
how much H2SO4 is needed to neutralize it ?

SYSTEMATIC REVIEW 203

417. One g. of coal gave 0.2000 g. of barium sulphate;
1 g. of magnesium oxide and 0.50 g. of sodium carbonate
were used in the analysis. It was found upon a blank
analysis of the reagents that 10 g. of the magnesia and
5 g. of sodium carbonate together gave 0.1500 g. of
BaSO4. What is the percentage of sulphur in the coal ?

418. In the analysis of a limestone, 1 g. was taken
for analysis, and a precipitate of CaSO4 weighing 0. 812 g.
was obtained. A precipitate of magnesium pyrophos-
phate weighing 0.385 g. was also obtained. What is
the percentage composition of the limestone in CaO
and MgO ?

419. Find the weight and volume of oxygen needed
for the complete combustion of 10 g. of C2H4.

420. How much CO2 in a room 10 m. x 6 m. x 4 m.,
if there is 1 volume CO2 in 10,000 volumes of air?

421. How many 1. of CO2 must be passed over hot
charcoal to give 100 g. of CO ?

422. Sixty 1. of steam require what volume of the
component gases ?

423. What volume of chlorine would be equal to 24 1.
of methane at 0° C. and 760 mm. ?

424. If 200 cc. of oxygen are exploded with 40 cc-
of marsh gas, what are the volumes and percentage
compositions of the residual gases ?

425. If 3.36 g. of three different metals liberate
respectively 1344 cc., 3136 cc., and 1636 cc. of hydro-
gen, what metal was dissolved in each case ?

426. What weight of alcohol and what volume of
CO2 on fermentation are produced by 21 g. of grape
sugar ?

204 PROGRESSIVE PROBLEMS IN CHEMISTRY

427. Gunpowder is composed of 75 parts niter, 15
parts charcoal and 10 parts sulphur. If all the carbon
forms CO2 and the nitrogen is liberated, find the
volume of these gases evolved on the explosion of 1 g.
of gunpowder at standard conditions.

428. At the ordinary temperature and pressure, water
absorbs 50 % of its weight of ammonia. Calculate the
amount of sal-ammoniac and quicklime needed to pro-
duce 10 Kg. of hartshorn.

429. According to Boussingault, a m.2 of leaf will
decompose in sunlight 1.108 1. of carbon dioxide
in an hour. Calculate in tons the amount of car-
bon assimilated in an hour by 1,000,000 trees, each
possessing 100,000 leaves and each leaf containing
25 cm.2 Calculate the volume of the carbon so
assimilated, on the assumption that it possesses a sp.
gr. of 2.6.

430. If sea water contains 0.36 parts MgBr2 in 1000,
how much of it would be needed to give 1 1. of bro-
mine (sp. gr. = 3.18)?

431. lodic acid may be obtained by passing a stream
of chlorine through water containing iodine in suspen-
sion ; how much iodine and chlorine will be needed to
prepare 100 g. of iodic acid ?

432. What weight of iron sulphide will be needed to
yield a 1. of hydrogen sulphide at 0° C. and 760 mm.,
and how much air will be required to burn this gas com-
pletely to water and sulphur dioxide ?

433. Manchester coal gas contains 35 % by volume of
marsh gas ; calculate the weight of this gas in a gas-
ometer holding 100,000 ft.3 of coal gas.

SYSTEMATIC REVIEW 205

434. If 100 g. of pure silver cyanide are shaken up
with 120 g. of hydrochloric acid containing 26.1% of
HC1, how much silver chloride is produced and what is
the percentage amount of hydrocyanic acid in solution?

435. A water solution of potassium iodide having
20 g. in it is treated with chlorine ; what volume of
chlorine will be needed to replace all the iodine ?

436. Sulphuric ether vapor is exploded with 60 times
its volume of air ; find volumes of residual gases.

437. If 300 cc. of oxygen were added to 200 cc. of a
mixture of H, CO and CH4, and if, after exploding, the
volume was 220 cc., and after washing with KOH so-
lution 80 cc., what was the composition of the mixture?

438. Five volumes of a hydrocarbon, CnH2ra, are sub-
mitted to combustion ; how many volumes of oxygen
are required for its complete combustion and how many
volumes of CO2 are generated ?

43d. Find weight of hydrogen necessary to unite
with oxygen in 200 g. of air to form water.

440. Find volume of oxygen needed to unite with
2 1. of hydrogen to form water. What volume with
(a) 60 cc. ; (5) 60 dm.3; (c) 60 1. ; (d) 60 qt. ;
0) 60 M.3; (/) 700 volumes?

441. Find the weight of (a) 700 cc. of dry hydrogen
at 0° C. and 760 mm. ; (5) of 2000 cc. ; (c) of 13 1.;
(d) 16J dm.3; (e) 3 m.3

442. One Kg. of water contains hydrogen and oxygen
in what proportion by weight and by volume ?

443. Find the weight of 1200 1. of phosphorus vapor.

444. Arsenic is burned in oxygen and 103 g. of the
oxide are produced ; how much arsenic was used ?

206 PROGRESSIVE PROBLEMS IN CHEMISTRY

445. A tank holds 20 g. of oxygen ; what weight (a)
of N2O and of (6) NO will it hold ?

446. If potassium is heated in contact with 10 g. of
N2O and NO separately, what volume of nitrogen will
be left in each case?

447. How much pure HNO3 in 200 tons of HNO3,
200 g. of which will neutralize 88.6 g. of pure NaOH ?

448. What loss in weight should 100 Ib. of gypsum
undergo when heated to + 250° C.?

449. If 0.4 g. of iron dissolved in acid gave 167.4 cc.
of hydrogen at -f 12° C. and 750 mm., what is the purity
of the iron?

450. How much coke (90 % pure carbon) would be
needed to make 100 m.3 of CO, measured at + 30° C.
and 850 mm.?

451. If 0.2 g. of a metal yield 77.39 cc. of hydrogen,
how much will yield 309 cc.?

452. If 600 cc. oxygen at + 12° C. and 720 mm. are
required, and the materials on hand are bleaching pow-
der, cobalt oxide and water, how much bleaching pow-
der will be used?

453. What volume of HI contains 2 g. of iodine at
standard conditions?

454. If 1 cc. HC1 neutralizes 0.0106 g. Na2CO3, what
weight of AgCl will be thrown down when 1 cc. is
added to excess of AgNO3 solution?

455. A mixed gas consists of hydrogen 46%, CH4
40%, and olefiant gas 14% by volume ; how much air
would be needed to burn 100 1. of this gas?

456. Find the weight of 20 1. of air containing 21 %
of oxygen and 79 % of nitrogen at 0° C. and 760 mm.

SYSTEMATIC REVIEW 207

457. In 300 g. of common alum, find how much alu-
minum is present.

458. A slab of marble weighs 200 Kg. (a) How
much lime will it make ? (6) What volume of water
will just slake this lime? (c) How many 1. of air will
transform it into the carbonate ? (1 volume of CO2 in
10,000 volumes of air.)

459. When 50 g. of ZnO were made, how much zinc
was needed and what volume of oxygen was used?

460. What weight of HC1 would be needed to dis-
solve 200 g. of ZnO?

461. If 20 cc. of H2SO4 solution yield 2.468 g. of
BaSO4 when precipitated with BaCl2, what weight of
this acid will be required to neutralize 10 g. of Na2CO3?

462. What volume of sulphuric ether vapor corre-
sponds in weight to (a) 11. of nitrogen ; (J) 1 1. of
air; (V) 1 1. CO2; (d) 1 1. of chlorine?

463. What weight of phosphoric acid could be made
from 10 Ib. of phosphorus?

464. On heating sodium phosphate till there is no
longer a loss in weight, one gets 100 g. of residue ;
what was the original weight?

465. An unknown volume of hydrogen sulphide re-
quired 110.34 cc. of chlorine for complete decomposi-
tion ; what was the volume of the hydrogen sulphide ?

466. One g. of NaCl in solution was mixed with an-
other solution containing 2 g. of AgNO3. Find weight
of residue. Which one was in excess and how much ?

467. How much CaC2 will produce enough gas from
water to yield on combustion 20 1. of CO2, measured at
+ 10° C. and 730 mm. ?

208 PROGRESSIVE PROBLEMS IN CHEMISTRY

468. If 25 g. of sodium acetate yield a certain weight
of CH4, what volume of air (21 % oxygen) is needed
to burn this gas?

469. If 24 g. of magnesium are heated in a current
of nitrogen, what is the weight of the product?

470. I need 2 1. of CO2. What weights of (a)
Na2CO3 and (5) NaHCO3 would have to be treated
with acid to give this volume?

471. What is the weight of 100 1. of SOa, measured
at + 31° C. and 721 mm. ?

472. What volume of CO, at + 800° C. and 700 mm.,
would be required to reduce 1 Kg. of ferrous oxide to
metallic iron ?

473. A 1. of mineral water yielded 0.0134 g. of Agl ;
how much iodine is contained in 1,000,000 cc. of the
water ?

474. From the vapor densities of these gases com-
pute their molecular weights : (a) oxygen, 16 ; (5) car-
bon dioxide, 22 ; (<?) nitrogen, 14; (<f) nitric oxide, 15;
(e) carbon monoxide, 14 ; (/) marsh gas, 8.

475. Find the vapor densities of these molecules,
computing the molecular weights by affixing the atomic
weights:' (a) HC1; (5) C2H2; (c?) NH3 ; (d) PH3 ;
0) 02; (/) P4; (g) Hg ; (A) CO ; (*) CH4.

476. (a) The vapor density of alcohol is 23. As-
certain which of the following is the proper formula
for alcohol: (1) C4H12O2 ; (2) C2H6O ; (3) C8H24O4.
(7>) The vapor density of acetic acid is 29.7, and the
percentage composition indicates one of these symbols.
Which is correct: (1) H2CO ; (2) H6C3O3 ; (3)
H4C2O2? (V) To which of these formulas does the
density 33.5 apply: (1) C1O2; (2) C12O4?

SYSTEMATIC REVIEW 209

477. What weight of calcium carbonate is required
to neutralize 400 cc. of hydrochloric acid solution which
contains 100 g. of the pure substance ?

478. The specific heat of phosphorus is 0.189. The
vapor density of phosphorus is 62. How many atoms
are there in the molecule of phosphorus gas ?

479. How much nitrogen may be obtained from 22 g.
of ammonium nitrite ? What volume would it occupy
at + 20° C. and 756 mm. pressure?

480. In every 100 parts of nitric acid there are 1.58
parts of H, 76.19 parts of O, and 22.23 parts of N.
Does this fix the formula of the acid? Why do we
accept the formula HNO3?

481. If 100 g. of gypsum are heated, what volume
of steam at + 300° C. is given off?

482. How much carbon dioxide by weight and by
volume can be obtained from 53 g. of sodium carbonate?
What volume would the gas occupy at + 20° C. and
under a pressure of 75 mm. ?

483. A 1. of a certain gas weighs 7.50 g., while a
1. of hydrogen under the same conditions weighs 0.050 g.
The atomic weight of the element composing the gas
is 75. How many atoms are there in one molecule of
the gas?

484. What volume of oxygen under standard condi-
tions can be obtained from 5 g. of potassium chlorate?

485. What is the atomic weight of silver, if the
specific heat is 0.056 and the atomic heat is 5.99 ?

486. Find the specific heat of silver, if the atomic
weight is 107 and the atomic heat is 5.99.

210 PROGRESSIVE PROBLEMS IN CHEMISTRY

487. Compute atomic heats from the data that
follow: (a) Hg, at. wt. 199, sp. ht. 0.033; (ft) iodine,
at. wt. 126, sp. ht. 0.054; (<?) U, at. wt. 238, sp. ht.
0.028 ; (d) Br, at, wt. 80, sp. ht. 0.1071.

488. Take 6.4 as the atomic heat of the following
and the specific heats as given, and find the approxi-
mate atomic weights: (a) Al, 0.22; (ft) Fe, 0.11;
(<?) Zn, 0.094 ; (d) K, 0.17 ; (e) Pb, 0.031.

489. Hydrogen is passed over hot copper oxide, and
the water that is formed is absorbed by calcium chloride
and its weight ascertained to be 3 g. ; what has been
the loss of weight of the tube containing the copper
oxide ?

490. Two 1. of a gas which is half oxygen and half
sulphur weigh 5.76 g. ; what is its formula ?

491. A compound of nitrogen and hydrogen, of which
the nitrogen is \$, weighs 0.765 g. to the 1.; what gas
is it?

492. Two 1. of a compound of oxygen and nitrogen
weigh 3.96 g. The nitrogen is ^ of the whole.
What is the compound ?

493. Find the specific heat of each of the following
elements from the constant atomic heat 6.4 : (a) Mg,
at. wt. 24 ; (ft) Ni, at. wt. 58 ; (c) Pt, at. wt. 193 ;
(cf) Na, at. wt. 23.

494. The atomic weight of copper is either 31.5 or
63; find which is correct if the specific heat is 0.094.

495. If zinc has an atomic weight of either 32.5 or
65 or 130, find which is correct if the specific heat of
Zn is 0.094.

SYSTEMATIC REVIEW 211

496. If 1 1. of acetylene is burned, what volume
of oxygen is necessary for the combustion and what
volume of carbon dioxide will be formed?

497. What weight of carbon dioxide would be
obtained by burning 17 g. of carbon ?

498. What volume of oxygen will unite with 730 cc.
of carbon monoxide to form carbon dioxide and what
will be the volume of the carbon dioxide produced?

499. Supposing standard conditions in each case,
find the weight of a 1. of ammonia, NH3; CO2; CO;
N2; H2S; N2O3 ; C12.

500. By analysis we find aluminum-methyl to con-
tain 37.5 % of Al, 50 % of C, and 12.48 % of H. The
vapor density is very nearly 72 at + 160° C., but at
+ 220° C. it is found to be nearly 36. Can you ac-
count for the vapor density varying at the two tem-
peratures ? What is the formula of the compound?

501. Carbon and oxygen form what compounds? If
1 1. of oxygen combines with carbon to form each of
these compounds, what will be its volume in each case,
at the standard temperature and pressure?

502. What is the sp. gr. referred to air and to hydro-
gen of a gas that requires 12 minutes to escape through
an opening, while the same volume of air under same
conditions of temperature and pressure requires 20
minutes ?

503. If an ore contains 10% of moisture and 12% of
copper, what will be the percentage of copper in the ore
dried at +105° C.?

504. If an ore contains 15 % of moisture and 50% of
manganese, what will be the percentage of manganese
in the dry ore ?

212 PROGRESSIVE PROBLEMS IN CHEMISTRY

505. What is the sp. gr. referred to air of a gas that
escapes in 14.5 minutes through an opening, through
which, at the same temperature and pressure, the same
volume of air requires 19.5 minutes ?

506. What is the vapor density of a gas that escapes
in 7 minutes and 30 seconds from an opening, while the
same volume of air under the same conditions requires
5 minutes and 10 seconds ?

507. If a sample of coal contains 10% of ash on the
dry basis, what is the percentage of ash in the natural
coal containing 5 % of moisture ?

508. A sample of ore contained 20 % of lead, 14 % of
zinc and 14% of water; what are the percentages of
lead and zinc on the dry basis ?

509. A clay was partially dried and then contained
SiO2, 50 %, and water 1 % ; the original clay contained
12 % of water ; what is the percentage of the silica in
the original sample ?

510. Find the proportion by weight and by volume
in which ethane gas will combine with oxygen.

511. A quantity of hydrogen measures 76 1. at
+ 100° C. and 746 mm. pressure; calculate its weight.

512. The equivalent of mercury is 100, and the for-
mula of mercuric chloride is HgCl2 ; find its specific
heat.

513. The formula of ethane is C2H6. Calculate the
density of its vapor (a) compared with hydrogen; (6)
compared with air.

514. If an ore contains 60% of iron in the dry sample,
what is the percentage of iron in the natural ore which
contains 10 % of water ?

SYSTEMATIC REVIEW 213

515. What is the amount of " available oxygen " in
a cc. of a solution of potassium permanganate contain-
ing 50 g. per 1. ?

516. Find the weight of 10 cc. of iron when sp. gr.

is 7.85.

517. If 100 g. of a solution of hydrogen dioxide in
water gave off, when heated, 5 1. of oxygen, what is
the percentage of H2O2 in the solution ?

518. What weight of potassium permanganate, in
acid solution, will be reduced by 5000 cc. of hydrogen
sulphide at standard conditions ?

519. Calculate the density (referred to air) of C2H4.

520. (#) The vapor density of chlorine is 35, the
atomic weight is 35 ; find the number of atoms per
molecule. (6) The vapor density of Zn is 32.5, its
atomic weight is 65 ; how many atoms in its molecule ?
(<?) Phosphorus has atomic weight 31, vapor density 62.
compute as before. (d) The atomic weight of ozone
is 16, its vapor density is 24 ; compute.

521. The atomic weight of copper is 63.3 and the
formula of copper chloride is CuCl2. The atomic weight
of silver is 108. Determine the specific heat of silver
and copper respectively.

522. What weight of ammonium chloride would be
required in order to prepare 5 Kl. of ammonia ?

523. How many cc. of nitrogen and of hydrogen
would be produced by decomposing 20 cc. of ammonia
by means of electric sparks ?

524. What volume and weight of air would contain
enough oxygen to burn exactly 25 1. of hydrogen ?

214 PROGRESSIVE PROBLEMS IN CHEMISTRY

525. What volume of chlorine would be required to
convert 20 1. of sulphur dioxide dissolved in water into
sulphuric acid, and what weight of sulphuric acid would
be produced ?

526. An iron rod 250 cm. long at -f 10° C. is 0.09
cm. longer at -f 40° C. ; what will its length be at
+ 60CC.?

527. What volume of chlorine at N.T.P. would be
required to convert an acidified solution of 5 g. of crys-
tallized ferrous sulphate into a ferric salt?

528. How many cc. of a solution of potassium dichro-
mate, containing 50 g. of the salt per 1., would be re-
quired to oxidize 5 g. of ferrous chloride to a ferric salt ?

529. What are the laws of diffusion of gases ? If 20
volumes of hydrogen take 10 minutes to diffuse out of
a vessel, how long will 50 volumes of oxygen take to
diffuse out under like conditions ?

530. If 0.428 g. of one of the oxides of manganese,
when heated with hydrochloric acid, gave 42 cc. of
chlorine, at N.T.P., which oxide of manganese was
used ?

531. Ferric oxide contains 30% of oxygen and its
molecule 3 atoms of oxygen ; what is its molecular
weight ?

532. If 1337 g. of copper sulphate yield 317 g. of
copper and its molecular weight is 267.4, how many
atoms of copper are there in a molecule of the sulphate ?

533. A sample of silver nitrate weighing 2.40 g. was
brought into solution and treated with a soluble chloride
(excess). The weight of silver chloride precipitated
was 2. 01 g. What was the purity of the sample ?

SYSTEMATIC REVIEW 215

534. What weight of zinc (98 %) will be required for
the liberation of the hydrogen from 10 g. of hydro-
chloric acid containing 39.1 % of HC1?

535. What weight of sulphuric acid containing
27.32 % H2SO4 will be required for interaction with
2.17 g. of iron wire (99% pure)?

536. On the top of a mountain the barometer stands
at 70 cm. and the temperature is +10° C., while in the
valley the barometer stands at 758 mm. and the ther-
mometer at + 20° C. ; what are the relative densities of
the air in the two places ?

537. If 0.2815 g. of calcite was dissolved in 30 cc. of
normal HNO3, and the excess of acid determined by
normal NaOH, of which 24.43 cc. were required, what
percentage of CO2 did the sample contain?

538. If 2.0876 g. of hydrogen, when passed over
heated oxide of copper, yielded 18.7406 g. of water, what
is the equivalent of oxygen ?

539. What is the absolute density of hydrogen at
+ 20° C. and 740 mm. pressure?

540. What is the absolute density of air at +10° C.
and 750 mm. pressure? The absolute density at the
standard conditions is 1.293.

541. If 400 cc. of gas, with the density 16, and
measured at +25° C. and 750 mm. pressure, are to
be brought to a temperature of + 10° C. and a pressure
of 760 mm., what weight of this final gas can be con-
tained in a vessel of 100 cc. capacity?

542. If 10 g. of a gas, measured at -48° C. and 600
mm. pressure, were expanded by heating to + 177° C.
and reducing the pressure to 480 mm., and the rarefied

216 PROGRESSIVE PROBLEMS IN CHEMISTRY

gas, 250 cc., weighed 0.5 g., what was the original volume
of gas and what was the density of the gas at its original
and final volume ?

543. If 10 1. of a gas, measured at + 20° C. and 750
mm. pressure, weighed 14 g., what weight of this gas
could be contained in a smaller vessel holding 4 1. at
+ 10° C. and 760 mm. pressure?

544. What volume will 1000 cc. of a gas at -f 300° C.
and 740 mm. pressure occupy when reduced to standard
conditions ?

545. A piece of metal weighing 30 g. displaced 20 cc.
of water; what is the relative density of this metal
referred to water?

546. A vessel weighing 6.448 g. weighed 7.963 g.
when filled with water and 8.266 g. when filled with a
salt solution ; what is the relative density of this solu-
tion referred to water?

547. What is the relative density of hydrogen sul-
phide referred to air and also to oxygen ?

548. What is the relative density of hydrogen chloride
referred to hydrogen, air, oxygen and chlorine?

549. If 8 g. of oxygen were mixed with 10.08 g. of
hydrogen, and both gases were measured at the stand-
ard conditions, what was the relative density of this
mixture?

550. A volume of gas, with the relative density
0.8757, was found to measure 1560 cc. when transferred
to a vessel over water at + 18° C. and 742.4 mm.; what,
is the weight of the dry gas here concerned?

551. What volume of chlorine, measured at + 10° C.
and 770 mm. pressure, would be required to convert
5 g. of phosphorus trichloride into the pentachloride ?

SYSTEMATIC REVIEW 217

552. What weight of pure sulphuric acid should be
obtained from 100 tons of "pyrites" containing 35 % of
sulphur ?

553. The coefficient of linear expansion of iron is
0.000011 ; how much must an iron rod 40 ft. long be
heated to expand 1 in. ?

554. If 240 cc. of gas at a pressure of 740 mm. were
admitted into an empty vessel of 800 cc. capacity, what
was the pressure of the gas at this new volume ?

555. If 500 cc. of oxygen, absolute density 1.429,
were compressed to a volume of 125 cc. at constant
temperature, what was the density of the gas at this
final volume ? What would be the weight of 50 cc. of
the compressed gas ?

556. A volume of gas measured 1 ft.3 at — 4° F. and
30 in. pressure ; what will be its volume at -f- 68° F.
and 39.4 in. pressure?

557. What volume of liquid carbon dioxide, measured
at 0° C., will be required to give 75 1. of the gas at 0° C.
and 760 mm. pressure?

558. If 0.352 g. of a sample of pyrolusite was heated
with hydrochloric acid, and the chlorine which was
evolved was passed into a solution of potassium iodide,
where it liberated 0.864 g. of iodine, what was the per-
centage of pure MnO2 in the sample ?

559. If 0.5 g. of pyrolusite containing 92% of pure
MnO2 was heated with strong hydrochloric acid, and
the resulting chlorine led into a solution of potassium
iodide, what amount of iodine would be liberated ?

560. If 35 cc. of a solution of potassium perman-
ganate containing 15 g. per 1. were required to oxidize

218 PROGRESSIVE PROBLEMS IN CHEMISTRY

50 cc. of acidified solution of ferrous sulphate to ferric
sulphate, what was the amount of metallic iron in a 1.
of the ferrous sulphate solution ?

561. What volume of chlorine, at + 17° C. and 750
mm. pressure, would be required to convert 6 g. of tin
into stannic chloride ?

562. A volume of gas weighing 5 g. was expanded at
a constant temperature till the pressure was reduced
to | of its former value, and 500 cc. of the rarefied
gas weighed 1.25 g. What was the original volume
of the gas ? Calculate also the original density,
assuming the original observations made at standard
conditions.

563. A volume of gas measuring 600 cc. at 760 mm.
pressure was expanded to a volume of 1000 cc. at con-
stant temperature ; what was the final pressure of the
gas?

564. A solution contains 48 g. of Pb (NO3)2 per 1.;
how much H2SO4 will 10 cc. of this solution
precipitate ?

565. Calculate the volume of chlorine liberated in the
action of 40 g. of potassium dichromate upon a hydro-
chloric acid solution.

566. If 0.535 g. of a sample of pyrolusite, when acted
on with a mixture of sulphuric acid and oxalic acid,
produce 0.48 g. of carbon dioxide, what was the per-
centage of pure MnO2 in the sample ?

567. The absolute density of oxygen is 1.429. When
a given volume of this gas is warmed from 0°C. to
+ 40° C. under a constant pressure, what will the abso-
lute density of the gas become ?

SYSTEMATIC REVIEW 219

568. A volume of gas with the absolute density 4 and
measuring 250 cc. at 0° C. was expanded by warming,
under constant pressure, to a volume of 600 cc. What
increase in temperature was required, and what would
be the weight of 300 cc. of the rarefied gas ?

569. If 500 cc. of a gas, the absolute density of
which is 6, must be reduced to a density of 0. 75 at con-
stant temperature, what will be the volume of this rare-
fied gas ? Calculate also the weight of 400 cc. of the
rarefied gas.

570. Calculate the relative density of hydrogen
chloride, 5 1. of which under standard conditions weigh
8.205 g.

571. Calculate the relative density of chlorine, 100
cc. of which at standard conditions weigh 0.322 g.

572. The sp. gr. of chlorine is 2.449; what is its rel-
ative density upon the oxygen standard?

573. What is the weight of BaO in 1.9327 g. of
BaCr04 ?

574. What is the weight of CaO in 2.9478 g. of
CaS04?

575. What weight of MnCO3 yields on ignition
1.450 g. of Mn3O4 ?

576. How much arsenic is there in 5 g. of As2S3 ;
of As2S5 ; of Mg2As2OT ?

577. How much Agl can be made from a Ib. of pure
silver ; how much AgBr ; how much AgCl ?

578. If 1.10 g. of stibnite gave on analysis 0.5987 g.
of Sb2O4, what was the percentage of antimony ?

579. Air liquefies at — 182° C. Express this temper-
ature on the Fahrenheit scale.

220 PROGRESSIVE PROBLEMS IN CHEMISTRY

580. When water in an open dish boils at -f 209° F.,
what would be the reading of an accurate barometer
placed near by ?

581. Reduce 12 1. of oxygen, measured at +47° C.
and under a pressure of 782 mm. of mercury, to the
standard conditions.

582. What will be the volume of 9 1. of hydrogen
when heated to + 120° C. and under a pressure of 423
mm.?

583. Given 27 cc. of nitrogen at + 14° C. and 752.1
mm., what will be its volume at -f 20° C. and 767.8
mm.?

584. What is the weight of 77.2 cc. of air, measured
over water at + 27° C. and 758 mm. pressure ?

585. What is the weight of 17 1. of Irydrogen, meas-
ured at + 12° C. and 3 atmospheres pressure ?

586. What is the weight of 85 cc. of NH3, measured
over mercury at + 140° C. and under a pressure of 770
mm.? Given the tension of mercury vapor at + 140° C.
= 1.76 mm.

587. Find the density referred to air of chloroform
vapor, given the following data for Dumas' method :
weight of bulb and air at + 20.5° C. and 763.9 mm. =
34.8451 g. ; weight of bulb and vapor at + 116.5° C. and
763.9 mm. = 35.8430 g.; volume of air in bulb at
+ 20.5° C. = 394.93 cc.

588. An object, the sp. gr. of which is 3.38, weighed
39.7250 g. in air when weighed with brass weights;
what is its true weight ?

589. An object, the sp. gr. of which is 0.95, weighed
17.8540 g. in air when weighed with brass weights;
what is its true weight ?

SYSTEMATIC REVIEW 221

590. A bar of gold, sp. gr. = 19.3, weighed 10.73685
Kg. when weighed in air with brass weights; what
is the true weight ?

591. A piece of pyrrhotite, sp. gr. = 4.58, weighed in
air 47.3854 g. when weighed with platinum weights ;
what is its true weight ?

592. A piece of antimony, sp. gr. =6.71, weighed
75 g. in air, the weights used being 50 g. brass, 20 g.
and 5 g. platinum ; what is the true weight ?

593. If 50 cc. of CH4, 50 cc. of H2, and 50 cc. of
C2H2 were mixed with 450 cc. of oxygen and exploded,
what would be the resulting volume at the same tem-
perature and pressure,? (Assume that the temperature is
below + 100° C.)

594. How many amperes are flowing in a circuit
which, in the course of 1 hr. and 15 min., has deposited
30.186 g. of silver?

595. How many g. of lead shot at + 200° F. must be
used to raise the temperature of 400 g. of water from
+ 40°F. to +90°F.?

596. How much alcohol at — 10° C. must be mixed
with 200 g. of chloroform at + 30° C., that the final
temperature may be + 10° C.?

597. If a 50 g. lump of silver, left in ice water until
it is cooled to 0° C., is dropped into 100 g. of ether
at -h 30° C., what will be the temperature of the mixture ?

598. We have at our command a waste acid from the
nitrating of glycerine, the composition of which is :
sulphuric acid, 62.18%; nitric acid, 19.07%; and
water, 18.75%. We also have an oil of vitriol contain-
ing 97 % by weight of H2SO4, and a commercial nitric

222 PROGRESSIVE PROBLEMS IN CHEMISTRY

acid containing 87% by weight of HNO3. What
weights of each must be taken to give 1000 Ib. of a
mixture containing 60% of H2SO4, 28% of HNO3,
and 17 % of water, without adding water ?

599. Bearing in mind that the molecule of mercury
vapor is monatomic, calculate the weight of 500 cc. of
that gas.

600. If we have two alloys, viz., a brass containing
65 % of copper and 35 % of zinc, and a German silver
containing 56 % of copper, 24 % of zinc, and 20 % of
nickel, supposing that there is no loss by oxidation or
volatilization during the fusion, what will be the com-
position of the alloy formed by melting these two alloys
together in such proportion that it contains 30 % of zinc ?

601. Suppose that we desire to prepare 100 Ib. of an
alloy containing 70 % of copper, 20 % of zinc, and 10 %
of tin ; we have at our command, pure copper, a brass
containing | copper and J zinc, and a solder containing
J zinc and J tin : how much of each must be taken ?

602. Given pure silver and an alloy containing 890
parts of silver and 110 parts of copper, how many oz.
of each must be taken to form 1000 oz. of an alloy
containing 925 parts of silver and 75 parts of copper ?

603. Given a mixture of silver chloride and silver
bromide, the weight of which is 1.5 g., analysis showing
the mixture to contain 1 g. of metallic silver, what are
the weights of the chlorine and of the bromine in the
mixture ?

604. The analysis of a dolomite gave 2 % of silica,
and the remainder was calcium and magnesium carbon-
ates. The determination of magnesia gave 10 % of
MgO. What was the percentage of carbon dioxide ?

SYSTEMATIC REVIEW 223

605. How many ft.3 of air at + 70° C. are needed for
the combustion of 1 Ib. of a coal having the analysis :
carbon, 90%; hydrogen, 5%; oxygen, 3.5%; nitro-
gen, 0.1%; sulphur, 0.5%. Assume the factor for
excess as 2.

606. Calculate the number of ft.3 of air at + 60° F.
needed for the combustion of 1 ton of a coal having
the composition: carbon, 74.60 %; hydrogen, 4.89%;
oxygen, 6.90%. Assume the factor for excess as 1.5.

607. How many calories are required to raise 500 g.
of a substance of specific heat 0.5 from +15° C. to

+ 37°C.?

608. How many g. of hot water at 4- 100° C. must be
poured into 3 1. of cold water at + 4° C. to warm it to
+ 20° C. ?

609. When 200 g. of hot water at + 80° C. are poured
into a pail of water at + 14° C., the temperature of the
mixture becomes + 20° C. How many g. of cold water
must there have been in the pail at first ?

610. If 80 g. of water at + 100° C. are poured into
80 g. of water at + 10° C., what will be the tempera-
ture of the mixture ?

611. If 500 g. of water at 4- 90° C. are poured into
600 g. of water at + 30° C., what will be the resulting
temperature ?

612. One Kg. of copper at 4- 100° C., when plunged
into 600 g. of water at + 10° C., raises the temperature
of the water to + 22° C. Find the specific heat of
copper.

613. Find the water equivalent, or thermal capacity,
of a brass calorimeter weighing 92 g.

224 PROGRESSIVE PROBLEMS IN CHEMISTRY

614. How many g. of mercury at -f- 98° C. must be
poured into 100 g. of water to raise its temperature
from + 5° C. to + 18° C. ?

615. How many calories of heat are required to raise
the temperature of (a) 5 g. of water + 10° C. ; (5) 8 g.
of zinc +20° C.?

616. How many calories of heat are given out (a)
when 2 Kg. of water cools + 90° C. ; (£>) when 700 g.
of copper cools from -f 250° C. to + 140° C.?

617. If 500 g. of water at + 5°C. and 500 g. of mer-
cury at 0° C. are each given the same quantity of heat,
how hot will the mercury become when the water has
been heated to + 10°C.?

CHAPTER XIV

A Progressive Series of Problems based on Equa-
tions taken from a recent text-book on
General Inorganic Chemistry

1. If 63 g. of sodium react with hydrogen monox-
ide, what is the weight of gas evolved?

2. If 32 g. of muriatic acid are treated with zinc,
how many g. of salt are produced ?

3. Zinc is boiled with caustic soda solution and 10 1.
of a gas are given off. Find weight of zinc and caustic
soda used.

4. A solution containing 27 g. NaOH is heated with
an excess of zinc. Find weight and volume of gas
produced.

5. What weight of oxygen and what other compo-
nent is required to make 100 g. of BaO2 ?

6. Sodium peroxide, when added to water, liberates
10 1. of oxygen at + 6° C. and 662 mm. Find weight
of NaOH produced.

7. What volume of ozone can be made from 300 g.
of oxygen ?

8. What weight of water is required to decompose
completely 23 g. of Na2O2?

9. What weight of NaOH can be made from 200 g.
of sodium monoxide ?

225

226 PROGRESSIVE PROBLEMS IN CHEMISTRY

10. On heating 392 g. of copper hydroxide, what
weights of products do you get ?

11. Into how many g. of the resultant gases do 222 1.
of HC1 decompose ?

12. In the synthesis of 100 g. of table salt, what
weights of the components are used and what volume of
the gaseous constituent is needed at | atmospheric
pressure and a temperature of + 10° C. ?

13. What volume of HC1 is needed to produce 30 g.
of MnCl2?

14. What weight and volume of oxygen will be
needed to liberate 102 m.3 of chlorine from muriatic
acid?

15. We need 2 tons of bromine. What weight of
chlorine is required and how much NaCl will be pro-
duced?

16. If 110 g. of Nal are decomposed by chlorine,
what are the weights of the products, and what is the
volume of chlorine at + 300° C. and 663 mm.?

17. If 222 1. of chlorine are dissolved in water and
exposed to the sun, what weights of materials will be
left after complete decomposition?

18. How much KOH would be needed to make 79 g.
of KC1?

19. Fluorine and water gave 63 1. of HF at 0° C.
and 771 mm. Find volume of fluorine used at — 10° C.
and 621 mm.

20. NaCl + H2SO4 will give either sodium sulphate
or sodium hydrogen sulphate according to the tempera-
ture. If 100 g. of H2SO4 are used in either case, what
weight of salt will be required?

PROBLEMS BASED ON EQUATIONS 227

21. NaBr will give what volume and weight of HBr
when treated with 16 g. of H3PO4?

22. PBr3 with 100 g. of H2O will give what weights
and what volume of gaseous product?

23. Of phosphorus 10 lb., of bromine 6 lb., and of
water 1 lb. are mixed. After complete reaction, what
weights of products and of excess do you get?

24. If 20 g. of HKF2 decompose, what weights of
wrhat substances result?

25. What weight of fluorspar will give 10 lb. of CaSO4
when treated with oil of vitriol? What volume of gas
will result at —40° C. and 2 atmospheres pressure?

26. An iron ore is 60 % silica. What weight of sam-
ple was taken if it requires 20 1. of HF to decompose it?

27. The decomposition of 2 lb. LiCl will give how
many 1. of chlorine at — 1° C. and 600 mm. ?

28. To make 1 Kg. of potassium, what weight of car-
bon and K2CO3 will be needed, and what volume of gas
will be evolved?

29. What weight of ammonium salt is required by
13 1. of nitrogen at +112° C. and 300 mm. ?

30. What weight of NH4NO3 will yield 21 1. of
laughing gas at standard conditions?

31. In the synthesis of 30 g. of ammonia, what vol-
ume of the components will be needed at + 13° C. and
900 mm. ?

32. What weight of water is required by 10 g. of
Mg3N2 for complete decomposition, and what volume
of gas will be evolved ?

33. NH4OH, on breaking up, gives 3 1. of NH3 at
0° C. and 760 mm. Find weight of hydroxide used.

228 PROGRESSIVE PROBLEMS IN CHEMISTRY

34. Sal-ammoniac is treated with 10 g. of KOH.
Find weights of resulting compounds.

35. If 20 g. of potassium and enough ammonia inter-
act, what weight and volume of hydrogen is produced?

36. What weight of salt is given by 300 cc. of HC1
+ NH3?

37. Lime water treated with 10 1. of CO2 at standard
conditions will give what weight of precipitate ?

38. How much acid calcium carbonate can be pro-
duced from 1 Ib. of slaked lime and sufficient CO2?

39. A14C3 on treatment with 12 Kg. of water will
give what volume of CH4 and what weight of precipi-
tate?

40. To produce 3000 cc. of CH4, what weight of
sodium acetate would be needed ?

41. What volume of oxygen would be needed to burn
300 cc. of marsh gas ?

42. If 2 1. of oxygen are heated with carbon, what
volume of gas is produced at | atmospheric conditions ?

43. If 100 Ib. of chalk are treated with HC1, what
weight of water will be produced ?

44. Magnesium is burned in a flask containing 20 1.
of choke damp at 0° C. and 760 mm. Find weight of
magnesium used and of carbon liberated.

45. To produce 20 1. of CO," what weights of sub-
stances are needed ?

46. Carbon is heated with 100 g. of oxygen. Find
the weight of the product.

47. How much H2O and CO2 will be needed to pro-
duce a gram molecule of formic acid ?

PROBLEMS BASED ON EQUATIONS 229

48. One ton of coke and steam reacting will give
what volume of gas at -f- 10° C. and 777 mm. ?

49. If 800 cc. of CO are passed over heated CuO,
what weight of copper is left ?

50. In the reduction of 100 tons of hematite, what
weight of CO will be needed and what weight of metal
will result ?

51. K2S5 + 100 g. of HC1 will give what weight of
sulphur; what volume of gas ?

52. Ca3(PO4)2 + 3 SiO2 + 5 C = 3 CaSiO3 + 5 CO +
2 P. Find weights of products when 3 Kg. of C. are
used ; find volume of CO at - 40° C. and 1000 mm.

53. Arsenopyrite is roasted with 10 g. of oxygen.
Find volume of gas evolved and As2O3 produced.

54. In the reduction of 200 g. of poisonous flour,
wkat weight of metal is produced ?

55. What weights of materials will be needed to
produce 100 Ib. of antimony ?

56. One Kg. sodium reacts on BaCl2. Find weight
of common salt produced.

57. We need 200 g. of boron; what weight of the
oxide and sodium will be needed ?

58. What weight of magnesium must be used to re-
duce 10 Kg. of B2O3 ?

59. What weight of aluminum can be made from the
double halogen salt of aluminum when treated with
100 g. of sodium?

60. In the Goldschmidt alumino-thermic process,
what weight of materials must be used to give 100 Ib.
of iron ?

230 PROGRESSIVE PROBLEMS IN CHEMISTRY

61. If 10 g. of aluminum are treated (a) with HC1 ;
(£) with NaOH ; (<?) with KOH, what is the weight of
products in each case ?

62. If 300 Ib. of sand are heated with carbon, how
much silicon will result ; what volume of gas at +81° C.
and | atmosphere ?

63. If 100 1. of CO are produced in the reduction of
SiO2 with C, what is the weight of metal freed ?

64. What volume of hydrogen at 2 atmospheres and
- 10° C. can be made from 300 g. of tin, and HC1 ?

65. What weight of tin oxide can be made by heating
20 g. of tin in air ?

66. If 400 g. K2SnO8 are made from tin, H2O and
KOH, what is the weight of each substance used ?

67. What volume of chlorine is needed to make 300
g. of SnCl4 from SnCl2 ?

68. Galena heated with 1 Kg. of oxygen will give
what volume of SO2 ; what weight of litharge ?

69. What weight of lead heated with air will produce
10 Ib. of lead monoxide? Find volume of air used.

70. When 30 g. of litharge and sufficient galena are
heated together to produce the metal, what weight of
products will they give?

71. If 10 g. of HC1, 20 g. of NaOH and 30 g. of
KOH each react on zinc, what in each case is the weight
of the product ?

72. Hematite is reduced by hydrogen. What weight
of iron can be made from 100 g. of ore ?

73. If 100 g. of cinnabar are roasted in air, what
weight of quicksilver results ?

PROBLEMS BASED ON EQUATIONS 231

74. Iron and CO interact. Find weight of iron
needed to give 100 1. of oxygen.

75. If 600 g. of H2O2 are made from Ba2O2, what
weight of oil of vitriol is needed ?

76. One 1. of ozone with H2O2 gives what volume of
oxygen ?

77. Ag2O and 100 g. of H2O2 will liberate what
weight of oxygen and of silver ?

78. What weight of iron sulphide will make 20 1. of
H2S?

79. Calcium phosphide treated with 100 g. of muri-
atic acid will liberate what volume of phosphine at
+ 1°C. and 766 mm.?

80. KOH + P4+ 3 H2O = 3 KH2PO2 + PH3. What
weight of KOH and of P are needed to give (a) 100
g. of PH3; (6) 31 1. of PH3 at +8° C. and 861 mm.?

81. 5 P2H4 = 6 PH3 + P4H2. Find weight of P4H2
produced when 17 g. of PH3 is liberated at -f 13° C.
and 750 mm.?

82. Arsenic is made from 3 g. of As2O3 and carbon.
How much carbon is needed?

83. SiMg2 + 4HCl=2MgCl2 + SiH4. If 30 g. of
HC1 are used, find weights of the other factors in the
equation.

84. If 30 g. ZnCl2 are made from ZnO, what is its
weight ?

85. 3 C12 + A12O3 + 3 C react. Find weight of A1C18
and volume of carbon monoxide if 10 g. of Cl are used.

86. Zinc is acted on by 20 1. of chlorine. What
weight of salt is produced ?

232 PROGRESSIVE PROBLEMS IN CHEMISTRY

87. A lunar caustic solution containing 20 g. is treated
with a " salt " solution. Find weight of residue left in
solution after filtering.

88. If 100 g. of iron are treated with 600 g. of iodine,
what weight of the iron iodide is made ?

89. In the following equation, if 1 Kg. of AgBr is
used, find the weight of the missing compound:
3FeCr204 + 2 AgBr + Ag2Br = Fe2(Cr2O4)3 + ? + 4 Ag.

90. NaAuCl4 + 3 Ag = NaCl + 3 AgCl -f- Au. In this
equation calculate the weight of gold when 100 g. of
silver are used.

91. 1 g. BC13 + water = what volume of gas and what
weight of B(OH)3?

92. Fire damp and chlorine interact, producing tetra-
chlormethane and 10 1. of ,HC1. Find weights of the
first two substances.

93. 100 g. CC14 + H2O = what volume of CO2 at
+ 33°C. and 555 mm.?

94. ' SiCl4 + 4 H20 = 4 HC1 + Si(OH)4.

30 g. + 80 g. ? ?

Find weights of the products and excess.

95. SiO2 and HF interact. If 30 g. of H2O are pro-
duced, find the volume of HF used at -f 60° C. and
760 mm.

96. 1 g. silicon fluoride is passed into an excess of
water. What volume of gas and weight of solid is left ?

97. What weight of metastannic acid is given by 3 g.
of stannic chloride with water ?

98. What weights of SiF4 and water result in the
production of 90 g. of H2SiF6 ?

PROBLEMS BASED ON EQUATIONS 233

99. TiCl4 + water = what weight of TiOC]2 when
2 1. of HC1 are given off ?

100. To produce 30 g. of H2SnO3, what weight of
SnCl4 was used ?

101. One 1. of lead nitrate solution is treated with
20 g. of salt and a complete precipitation occurs. Find
the percentage of lead salt in the solution.

102. What weight and what volume of chlorine is
liberated by 100 g. of PbO2 + HC1 ?

103. PC13, AsCl3, BiCl3 and SbCl3 + excess of water
= what weight of the oxy chlorides when 4 1. of HC1
are liberated in each case ?

104. 10 g. PC13 + 3 H2O = 3 HC1 + ?
10 g. PC15 + H20 = 2 HC1 + ?
10 g. POC13 + 3 H2O = 3 HC1 + ?
10 g. PC16 + 4 H2O = 5 HC1 + ?

In these equations find the weight of the compound
formed in each case.

105. 2 CuSO4 + K4Fe(CN)6 = Cu2Fe(CN)6 + ?

If 100 g. of K4Fe(CN)6 are taken, what weight of
bluestone is used, and what weight of the missing term
is produced?

106. Copper heated with 1 m.3 of air will yield what
weight of oxide ?

107. 2 Kg. of P2O6 contain what weight of P and
what volume oxygen ?

108. A 3 1. flask of O acts on ZnS. Find the weight
of products.

109. On roasting 800 g. of As2S3, what volume of O
is needed and what volume of gas is produced ?

234 PROGRESSIVE PROBLEMS IN CHEMISTRY

110. If 100 g. of CuSO4 in solution are treated with
a solution of KOH and the precipitate is heated, what
weight of products results ?

111. Limestone is heated till all the gas is driven off.
It measures 109 1. Calculate the weight of gas and of
oxide produced.

112. What weight of oxide and of water is formed
by 20 g. of B(OH)3?

113. Lime -f- 300 Ib. of water = what weight of cal-
cium hydroxide ?

114. P2O5 and H2O interact and form 100 g. of ortho-
phosphoric acid. Find weight of P2O5 and volume of
H2O at 0° C. and 760 mm.

115. What weight and volume of H are liberated by
2 Kg. of sodium thrown on water ?

116. Ferric chloride + 30 cc. of NaOH solution (50 % )
will yield what weight of precipitate ?

117. Sulphuric anhydride + a ton of water produce
what weight and volume of acid ? (Sp. gr. of H2SO4
= 1.84.)

118. What weight of Na2O and of H2O are required
to produce 100 g. of NaOH ?

119. What weight of NaOH will be required to
neutralize 300 cc. N/2 H2SO4 solution?

120. Na2O 4- 100 g. of water will form what weight
of caustic soda ?

121. What weight of CuS will be precipitated by
27 1. of H2S at + 20° C. and 667 mm. from excess of
copper solution ?

122. Green vitriol -f (NH4)2S give 100 g. of FeS.
Find weights of substances used.

PROBLEMS BASED ON EQUATIONS 235

123. Muriatic acid in excess reacts on 100 g. of FeS.
Find volume of gas evolved at — 13° C. and 500 mm.

124. To slake 1 ton of lime what volume of water at
0° C. would be needed, and what weight of Ca(OH)2
would be produced ?

125. From 1000 Kg. of Na2CO3, what weight of NaOH
can be made ?

126. To produce 100 1. of oxygen what weight of
Na2O2 would be needed and what volume of H2O in
cc. would be used ?

127. Na2SO4 + C = what weight of products, if 3 Kg.
of carbon are used ?

128. H2S and 3 g. of potassium will liberate what
volume of gas at + 20° C. and 777 mm. ?

129. CuO + 100 g. of H2SO4 will yield what weight
of water ?

130. CuCl2 with caustic soda solution containing 50
g. yields what weight of Cu(OH)2 ?

131. On boiling 300 g. of copper hydroxide with
water, what weights of materials result ?

132. CuOH on being heated yields 10 g. of Cu2O ;
what weight of water will be formed ?

133. AuO,OH + NaOH = H2O + NaAuO2. If 41
g. of NaOH are used, what weight of NaAuO2 will
result ?

134. A bin of lime is treated with 10 tons of water,
which just slakes it. A house is plastered with this
lime made into mortar. Find the volume of CO2
needed to convert all the mortar into CaCO3.

135. CaSO4 on being heated with 2 Kg. of carbon
yields what weights of materials ?

236 PROGRESSIVE PROBLEMS IN CHEMISTRY

136. When 30 g. of ZnSO4 are treated with NaOH
solution, they will yield (a) what weight of Zn(OH)2 ;
(6) what weight of compound when NaOH is used in
excess ?

137. Mercurous nitrate with 30 g. of NaOH gives
what weight of Hg2O ?

138. Hg2O on exposure to light yields 30 g. of mer-
cury. Find weight of Hg2O used and of residue other
than Hg left.

139. H2S is passed into a solution containing 100 g.
of HgCl2. What volume of gas is used to bring about
complete precipitation ?

140. KI solution containing 30 g. reacts on (a) HgNO3
solution ; (b) Hg(NO3)2 solution. Find weight of re-
sulting salt in each case.

141. NH4OH, when mixed with 20 g. of A12(SO4)3 in
solution, yields how many g. of residue ?

142. A12(SO4)3 + 100 g. (NH4)2S will produce what
weight of the sulphide of the metal?

143. A12S3 + excess of water gives 200 g. of A1(OH)3.
Find weight of A12S3.

144. In the Le Blanc process what weight of mate-
rials can be made from 300 Kg. of common salt?

145. Sodium sulphide with 200 Kg. of powdered
limestone produces what weight of CaS?

146. From 10,000 1. of NH3 -f sufficient CO2 and
water, how many Kg. of sodium dicarbonate may be
produced?

147. Washing soda + water and 3000 1. of CO2 at
— 8° C. and 900 mm. will produce what weight of the
dry product?

PROBLEMS BASED ON EQUATIONS 237

148. Bicarbonate of soda with 30 1. of HC1 will gener-
ate what volume of gaseous product?

149. Silver nitrate with 21 g. of Na2CO3 gives what
weight of precipitate ?

150. Washing soda reacting on 1 Kg. of sugar of lead
will throw down what weight of residue in solution ?

151. 3 PbC03 + H20 = Pb3(C03)2(OH)2 + C02. If
500 1. of CO2 are liberated, what is the weight of basic
salt produced?

152. What volume of HF will be needed to use up
20 g. of quartz, and what weight of gas will be pro-
duced?

153. Na4SiO4 is made from SiO2 and 300 g. of Na2O.
What weight of Na4SiO4 was produced ?

154. K4SiO4, on treatment with 200 1. of HC1, pro-
duces what weight of orthosilicic acid and of KC1?

155. Sodium sulphide + 100 g. of SnS2 = Na2SnS3.
Find weight of Na2S.

156. Copper + 2 Kg. of aqua fortis will yield what
weight of Cu(NO3)2, and what volume of nitric oxide
at + 30° C. and 900 mm. ?

157. As203 + 2HN03 + 2H20 = 2H3As04 + ?

If 100 g. of As2O3 are used, find weight and volume of
gas not given in equation.

158. • To make 10 g. of nitrous acid, what weights of
N2O3 and H2O are needed?

159. If 37 1. of oxygen are mixed with 39 1. of nitric
oxide, what volume of a new gas results and what
volume of residue is left ?

160. Lead nitrate on being heated yields 30 1. of
oxygen. Find weight of lead nitrate heated.

238 PROGRESSIVE PROBLEMS IN CHEMISTRY

161. How much HNO3 would 100 Kg. of N2O5 make
with water?

162. Chili saltpeter treated with 300 Kg. of H2SO4
will yield what weight of HNO3?

163. What volume of chlorine will be liberated from
100 g. of HC1 and enough HNO3 to make aqua regia ;
and with what weight of gold will this unite ?

164. Given 300 g. of AuCl3, what weight of SnCl2
will be required to precipitate all the gold?

165. What volume of HNO3 (sp. gr. 1.42) will be
needed to dissolve 31 g. of silver and what volume of
gas will be evolved?

166. KC1 and NaNO3 are allowed to act on each
other ; 300 Kg. of KNO3 result. What weights of the
salts were used?

167. What weight of H3PO3 will yield 17 1. of PH3?

168. From 75 g. of P2O5 + water, what weight of
orthophosphoric acid results?

169. A mass of apatite is treated with 100 tons of
H2SO4; what weight of CaH4(PO4)2 will be formed?

170. One ton of Ca3(PO4)2 on treatment with acid
will produce what weight of CaSO4 and of CaHPO4?

171. P4 + 3NaOH + 3H20 = 3NaH2P02 + PH3. If
300 g. of phosphorus are used, what are the weights of
the other members of the above equation, and what is
the volume of the gas at — 31° C. and 599 mm.?

172. H3 AsO4 is made from As2O5 and 10 g. of water.
Find weight of materials used and produced.

173. Na2S2O3 -f- 1 Kg. HC1 = what weight of sulphur
and what volume of SO9?

PROBLEMS BASED ON EQUATIONS 239

174. CuO and 750 g. of H2SO4 produce what weights
of products?

175. One g. of Na2CO3 and 1 g. of BaCl2 are sepa-
rately treated with H2SO4. Find weights of products.

176. PbS is roasted with oxygen. If a ton of PbSO4
is produced, what volume of oxygen has been used at
1 atmosphere pressure and + 26° C. ?

177. Se + 3 C12 + 4 H20 = 1 Kg. of H2SeO4 + 6 HC1.
Find weights of members on left side of equation and
volume of HC1 produced.

178. 2Cr(OH)2=21g.ofCr203 + H20 + H2. Cal-
culate the weights of solids in equation and volume of
gas.

179. CrCl3 + 20 g. of caustic soda produce what
weight of salt and of Cr(OH)3?

180. One Kg. of Cr(OH)3 = what weight of CrO, OH
and of H20 ?

181. On heating 100 g. CrO3, what weight of Cr2O3
do you get and how many m.3 of O ?

182. K2CrO4 is decomposed with 1 Kg. of H2SO4.
Find weight of K2CrO4 used and of K2Cr2O7 produced.

183. K2Cr2O7 is treated with 30 g. of KOH in solu-
tion. Find weight of material used and produced.

184. Na2Cr2O7 is changed by 10 g. of KC1 into
K2O2O7. Find weight of NaCl produced.

185. On heating 1 Kg. of K2Cr2O7, what weights of
normal chromate, Cr2O3, and volume of oxygen do you
get?

186. Oil of vitriol with 376 g. of K2Cr2O7 produces
what weights of materials and what volume of gas at
-22°C. and941mrn.?

240 PROGRESSIVE PROBLEMS IN CHEMISTRY

187. Cr2(SO4)3 + 23 g. of (NH4)2S will produce what
weight of Cr2S3 and of ammonium sulphate ?

188. Cr2S3, on treatment with 99 cc. of H2O at 0° C.
and 760 mm., yields what weight of substances?

189. Sugar of lead + 10 g. of K2Cr2O7 = how much
precipitate ? A lead salt + 32 g. of K2CrO4 produces
what weight of lead chromate ?

190. One Kg. of corrosive sublimate is made from
what weights of HgO and chlorine?

191. To make 30 g. of HOC1, how much C12O and
H2O must be used ?

192. C12 + H2O = HC1 + HOC1. If 21 1. of chlorine
at + 8° C. and 600 mm. are used, find volume of HC1
produced at standard conditions.

193. HgO, water, and 333 1. of chlorine are placed in
a vessel. How many g. of HgCl2 and of HOC1 were
produced ?

194. Through a KOH solution is passed 13 1. of
chlorine. Find the weight of KOC1 made.

195. If 3 tons of slaked lime are treated with chlorine,
what is the weight of bleaching powder produced?

196. Given 25 g. of HOC1, what volumes of HC1 and
of O are produced when it is exposed to sunlight ?

197. HOC1+ 3 g. of HC1 give what weight of chlo-
rine and of water?

198. CaCl(OCl) 4- 8 g. of H2SO4 = what weight of
CaSO4 and of HOC1?

199. 2 CaCl(OCl) + H2O + CO2 = CaCO3 + CaCl2-h
2 HOC1. If 13 1. of CO2 are used, find weight in g. of
resulting substances.

PROBLEMS BASED ON EQUATIONS 241

200. When 13 g. of NH3 react on NaBrO, what vol-
ume of nitrogen is given off?

201. 3 NaBrO + 100 g. CO(NH2)2 = what weight of
NaBr, H2O, N, and CO2 ?

202. 3 HOC1 = HOC1O2 + 2 HC1. If 41 1. of HC1
are produced, what is the weight of HOC1 used?

203. Should 30 g. of KOC1 break up, find weight of
KOC1O2 and of KC1 produced.

204. In the making of KC1O3, 100 1. of chlorine were
passed through a solution containing 300 g. of KOH.
Find the weight of KC1O3 made and of the substance in
excess.

205. Ca(ClO3)2 + 100 g. of KC1 = what weight of
CaCl2 and of KC1O8?

206. One Kg. of barium chlorate is treated with H2SO4
in excess. Find weight of precipitate and of HC1Q3.

207. HC1O3 + 5 g. of HC1 = what weight of H2O
and of chlorine ?

203. To make 100 g. of HC1O3, what weights of C12O5
and of water are needed?

209. C12O4 + 30 g. H2O = how many g. of HC1O3 and
ofHC102?

210. We need 80 g. of HC1O2. How much C12O3
must be dissolved in water to produce it ?

211. Should one need to make 30 g. of HIO3, what
weight of I2O5 and of H2O are needed ?

212. 2HI03+5S02 + 4H20 = 5H2S04 + I2. To
produce 30 g. of iodine what volume of SO2 at — 9° C.
and 861 mm. should be used ?

213. 2 HC1O3=HC1O2 + HC1O4. Should 20 g. of
HC1O3 be used, what weight of HC102 will result ?

242 PROGRESSIVE PROBLEMS IN CHEMISTRY

214. Ba(ClO4)2 + 10 cc. of H2SO4 (sp. gr. = 1.84)
will produce what weight of residue and of HC1O4 ?

215. If 77 g. of KC1O3 are heated just to fusion,
what weights of KC1O4, KC1, and O will result ?

216. 1 g. HC1O4 on treatment with iodine yields how
manyg. of HIO4andCl?

217. To make 39 g. of Mn(OH)2 what weight of
MnCl2 must be taken and how many cc. of a 40 %
NaOH solution will be needed ?

218. Mn2(SO4)3 + 90 cc. of NaOH (25 % solution)
•will yield how many g. of Mn(OH)3 and of Na2SO4?

219. To produce 21 1. of oxygen, what weights of
KMnO4 and of H2SO4 are required ?

220. 2 KMnO4 + 10 FeSO4 + 8 H2SO4

= K2SO4 + 2 MnSO4 + ? + ?

Should 800 g. of KMnO4 be used, find weights of
missing terms in the above equation.

221. To make 31 g. of H2SO4 what weights of
KMnO4, SO2, and H2O are required ?

222. 2 KMn04 + 5 H2O2 + 3 H2SO4

==?+? + 8H20 + 5O2.

If 13 g. of H2O2 are used, what weights of missing
members of equation and 1. of oxygen are produced ?

223. 2 KMnO4 + 5 C2H2O4 + 3 H2SO4

= ? + ? + 10 CO2 + 8 H2O.

If 20 g. of CO2 are produced, calculate the weight of
KMnO4 used and of missing factors in equation.

224. 10 g. manganese chloride with (NH4)2S yields
how many g. of NH4C1 and of MnS ?

225. Ferric sulphate with 300 g. of caustic soda in
solution produces what mass of ferric hydroxide ?

PROBLEMS BASED ON EQUATIONS 243

226. From 80 g. of ferrous sulphate + (NH4)2S what
mass of FeS will result ?

227. To make 3 tons of CaC2 what weights of lime
and C are needed?

228. A million m.3 of C2H2 are required. How
many Kg. of materials will be used and what weight
of residue will be left?

229. BN + 3 H2O = B(OH)3 + NH3. To produce
80 cc. of NH3 what weight of BN must be taken ?

230. NaNH2 + 31 cc. of H2O will give what weight
of NaOH and what volume in 1. of NH3 at + 31° C.
and 800 mm. pressure?

231. Mercuric cyanide on being heated breaks up
into 3 g. of Hg and (CN)2 ; what weight was heated ?

232. Potassium cyanide on treatment with 2 g. H2SO4
gives what volume of HCN at + 17° C. and 770 mm. ?

233. From 2 Kg. of CaCN2 + H2O how many g. of
Ca(OH)2andof H2CN2?

234. K4Fe(CN)6 is reduced with 30 g. of K. What
weight of Fe and of KCN are left ?

235. Litharge + 1 g. of KCN = what weight of Pb
and of KCNO ?

236. KCN and 3 g. of AgNO3 will give what mass of
saltpeter and of AgCN?

237. 3 K4Fe(CN)6 + 4 FeCl3 = Prussian blue + 12
KC1. Should 8 g. of FeCl3 be used, find the weight
of Prussian blue produced.

238. 2 K3Fe(CN)6 + 3 FeSO4 = 3 K2SO4 + Turnbull's
blue. What weight of Turnbull's blue can be made
from 81 g. of FeSO4 ?

APPENDIX

I. — INTERNATIONAL ATOMIC WEIGHTS, 1911

Aluminium
Antimony

Symbol
. . . . Al
Sb

Atomic
Weight
27.1
120.2

Molybdenum . . .
Neody mi um

Symbol
. Mo
. Nd

Atomic
Weight
96.0
144 3

Argon

A.

39 88

Neon ... .

Ne

20 2

Arsenic

As

74 96

Nickel

Ni

58 68

Ba

137 37

N

14 01

Bismuth

. . . . Bi

208.0

Osmium

. Os

190.9

Boron

... B

11.0

Oxvsren

. O

16 00

Bromine

Br

79 92

Palladium .

Pd

106 7

Cadmium .

. . . . Cd

112.40

Phosphorus

. p

31.04

Cs

132 81

Pt

195 2

Calcium .

. . . . Ca

40.09

Potassium . . . .

. K

39.10

Carbon

. . C

12 0

Praseodymium

. Pr

140 6

Ce

140 25

Radium

Ra

226 4

Cl

35 46

Rh

102 9

Chromium

. . . Cr

52.0

Rubidium .

. Rb

85.45

Cobalt

. Co

58.97

Ruthenium

Ru

101 7

Columbium .

. . . . Cb

93.5

Samarium ....

. Sa

150.4

Copper

. . . . Cu

63.57

Scandium . . . .

. Sc

44.1

Dysprosium

. Dy

162.5

Selenium ....

. Se

79.2

Erbium

. . . . Er

167.4

Silicon

. Si

28.3

Europium

. Eu

152.0

Silver

As

107 88

Fluorine . .

. . . . F

19.0

Sodium

. Na

23.00

Gadolinium

. . . . Gd

157.3

Strontium .

. Sr

87.63

Gallium .

. . . . Ga

69.9

Sulphur

. S

32.07

Germanium

... Ge

72 5

Ta

181 0

Glucinum

Gl

9 1

Tellurium

Te

127 5

Gold

Au

197 2

Terbium

Tb

159 2

Helium .

.... He

3 99

Thallium

. Tl

204.0

Hydrogen

. . H

1 008

Th

232 4

Indium .

In

114 8

Thulium

Tm

168 5

Iodine

I

126 92

Tin

Sn

119 0

Iridium .

. . . . Ir

193.1

Titanium ....

. Ti

48.1

Iron . . .

. . . . Fe

55 85

Tungsten

. W

184.0

Krypton

... Kr

82 92

. U

238.5

Lanthan um

. . . La

1390

Vanadium ....

. V

51.06

Lead

. . Pb

207 10

. Xe

130.2

Lithium

Li

6 94

Lu

1740

(Neo-ytterbium)

. Yb

1720

Magnesium .

. Mg

24.32

Yttrium

. Yt

89.0

Manganese •

. . . . Mn

54.93

Zinc

. Zn

65.37

Mercury .

. Hff

200.0

Zirconium .

. Zr

90.6

245

246

APPENDIX

> °«

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o w

~ «°«

pou9<£

* I 1 s S 3

oil* I « I

^ «, S w 2 s. '

i ? s i si i

5 is

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US

en

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a '

I

7

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APPENDIX

247

III.— THE METRIC SYSTEM

The fundamental unit of the metric system is the Meter (the unit of
length). From this the units of mass (Gram) and capacity (Liter) are
derived. All other units are the decimal subdivisions or multiples of
these. These three units are simply related, so that for all practical
purposes the volume of one kilogram of water (one liter) is equal to
one cubic decimeter.

PREFIXES

MEANING

UNITS

Milli-

= one thousandth

T^OlT

.001

Centi-

= one hundredth

TtfTF

.01

Deci-

= one tenth

A

.1

Meter for length

unit

= one

1.

Gram for mass

Deka-

= ten

¥

10.

Liter for capacity

Hecto-

= one hundred

10.Q

100.

Kilo-

= one thousand

ioT<m

1000.

The metric terms are formed by combining the words "Meter,"
Liter " with the six numerical prefixes.

Length

10 milli-meters mm. = 1 centi-meter

10 centi-meters
10 deci-meters
10 meters
10 deka-meters
10 hecto-meters

= 1 deci-meter

= 1 Meter (about 40 inches)

= 1 deka-meter

= 1 hecto-meter

= 1 kilo-meter (about f- mile)

; Gram," and

em.

dm.

m.

dkm.
hm.
km.

Mass

mg. = 1 centi-gram eg.

= 1 deci-gram dg.

= 1 Gram (about 15 grains) g.

= 1 deka-gram dkg.

= 1 hecto-gram hg.

= 1 kilo-gram (about 2 pounds) kg.

Capacity

= 1 centi-liter cl.

= 1 deci-liter dl.

= 1 Liter (about 1 quart) 1.

= 1 deka-liter dkl.

= 1 hecto-liter (about a barrel) hi.

= 1 kilo-liter kl.
The square and cubic units are the squares and cubes of the linear units.
The ordinary unit of land area is the " Hectare " (about 2£ acres).

10 milli-grams
10 centi-grams
10 deci-grams
10 grams
10 deka-grams
10 hecto-gram s

10 milli-liters
10 centi-liters
10 deci-liters
10 liters
10 deka-liters
10 hecto-liters

ml.

248

APPENDIX

EQUIVALENTS
1 Meter = 39.37 Inches

Legal equivalent adopted by Act of Congress, July 28, 1866

Length

Centimeter

= 0.3937

inch

Meter

= 3.28

feet

Meter

= 1.094

yards

Kilometer

= 0.621

statute mile

Kilometer

= 0.5396

nautical mile

Inch

= 2.540

centimeters

Foot

= 0.305

meter

Yard

= 0.914

meter

Statute mile

= 1.61

kilometers

Nautical mile

= 1.853

kilometers

Area

Sq. centimeter
Sq. meter
Sq. meter
Hectare
Sq. kilometer

Sq. inch
Sq. foot
Sq. yard
Acre
Sq. mile

0.155 sq. inch

10.76 sq. feet

1.196 sq. yards

2.47 acres

0.386 sq. mile

6.45 sq. centimeters

0.0929 sq. meter

0.836 sq. meter

0.405 hectare

2.59 sq. kilometers

Volume

Cu. centimeter = 0.0610 cu. inch
Cu. meter = 35.3 cu. feet
Cu. meter = 1.308 cu. yards

Cu. inch = 16.39 cu. centimeter

Cu. foot = 0.0283 cu. meter

Cu. yard = 0.765 cu. meter

APPENDIX

249

EQUIVALENTS —Continued
Capacity

Milliliter

= 0.0338 U. S. liq. ounce

Milliliter

= 0.2705 U. S. apoth. dram

Liter

= 1.057 U. S. liq. quarts

Liter

= 0.2642 U. S. liq. gallon

Liter

.= 0.908 U. S. dry quart

Dekaliter

= 1.135 U. S. pecks

Hectoliter

= 2.838 U. S. bushels

U. S. liq. ounce

= 29.57 milliliters

U. S. apoth. dram

= 3.70 milliliters

U. S. liq. quart

= 0.946 liter

U. S. dry quart

= 1.101 liters

U. S. liq. gallon

= 3.785 liters

U. S. peck

= 0.881 dekaliter

U. S. bushel

= 0.3524 hectoliter

Weight

Gram

= 15.43 grains

Gram

= 0.772 U. S. apoth. scruple

Gram

= 0.2572 U. S. apoth. dram

Gram

= 0.0353 avoir, ounce

Gram

= 0.03215 troy ounce

Kilogram

= 2.205 avoir, pounds

Kilogram

= 2.679 troy pounds

Metric ton

= 0.984 gross or long ton

Metric ton

= 1.102 short or net tons

Grain

= 0.0648 gram

U. S. apoth. scruple

= 1.296 grams

U. S. apoth. dram

= 3.89 grams

Avoir, ounce

= 28.35 grams

Troy ounce

= 31.10 grams

Avoir, pound

= 0.4536 kilogram

Troy pound

= 0.373 kilogram

Gross or long ton

= 1.016 metric tons

Short or net ton

= 0.907 metric ton

250

APPENDIX

Area of triangle
Area of triangle

Mensuration Rules

= \ (base x altitude).

Area of parallelogram
Area of trapezoid
Circumference of circle

Diameter of circle

Area of circle

Area of ellipse
Area of regular polygon
Lateral surface of cylinder
Volume of cylinder

Surface of sphere

Volume of sphere

Surface of pyramid \
Surface of cone J
Volume of cone

= Vs (s — a) (s — 6) (s — - c) , where

s= i(« + & + C).
= base x altitude.

= altitude x | sum of parallel sides.
= diameter x 3.1416.
_ ( circumference -=-3.1416.
~ I circumference x 0.3183.

( diameter squared x 0.7854.
~ I radius squared x 3.1416.
= product of diameters x 0.7854.
= £ (sum of sides x apothem).

circumference of base x altitude.

area of base x altitude.

f diameter x circumference.

\4 x 3.1416 x square of radius.

f diameter cubed x 0.5236.

A | of radius cubed x 3.1416.

I (circumference of base x slant

height) .

\ (area of base x altitude) .

APPENDIX

251

IV. — SPECIFIC GRAVITY OF GASES*

Name

Formula

Molecu-
lar
Weight

Specific Gravity,
Air = 1

Weight in
Grams of 1
Liter at 0°,
760 mm. at
Sea Level,
lat. 45°.

Calcu-
lated

Observed

Acetylene ....
Air
Ammonia ....

C2H2

NH3
A
AsH3
Br2
C4H10
C02
CO
COS
C12
C2N2
C2H6
C2H4
F2
He
HBr
HC1
HF
HI
H2
H2Se
H2S
H2Te
Kr
CH4
Ne
NO
N20
N2
N2+A etc.
N02
N204
NOC1
02
PH3
C3H6
SiF4
S02
X

26.016

17.064
39.9
78.024
159.92
58.08
44.00
28.00
60.06
70.90
52.08
30.048
28.032
38.0
4
80.968
36.458
20.008
127.98
2.016
81.216
34.076
129.62
81.8
16.032
20
30.04
44.08
28.08

46.04
92.08
65.49
32.00
34.024
42.048
104.4
64.06
128

0.8988
1.0000
0.5895
1.379
2.696
5.5249
2.0065
1.5201
0.9673
2.0749
2.489
1.7993
1.0381
0.9784
1.313
0.1382
2.7973
1.2595
0.691
4.4172
0.06965
2.806
1.1773
4.478
2.826
0.5539
0.691
1.0378
1.5229
0.9701

1.5906
3.1812
2.2625
1.1055
1.175
1.4527
3.607
2.2131
4.422

0.92

0.5971
1.379
2.695
5.524(227.9°)
2.01
1.52909
0.96716
2.1046
2.491
1.8064
1.075
0.9852
1.26
0.1368
2.71
1.2692
0.7126
4.3757
0.06960
2.795
1.1895
4.489
2.818
0.5576
0.674
1.0367
1.5301
0.96737
0.97209
1.60 (135°)
2.65 (26.7°)
2.31
1.10535
1.214
1.498
3.60
2.2639
4.422

1.1620
1.29330
0.7621
1.7828
3.485
7.1426
2.594
1.9652
1.2506
2.6825
3.1666
2.3261
1.3421
1.2520
1.697
0.1787
3.6163
1.6283
0.894
5.7106
0.089873
3.627
1.5230
5.789
3.654
0.7160
0.893
1.3402
1.9688
1.2542
1 .25718
2.0563
4.1126
2.925
1.4290
1.520
1.8780
4.663
2.8611
5.717

Arsine

Bromine ....

Carbon dioxide . .
Carbon monoxide .
Carbon oxysulphide
Chlorine ....
Cyanogen ....
Ethane . . .

Ethylene ....
Fluorine ....
Helium

Hydrobromic acid .
Hydrochloric acid .
Hydrofluoric acid .
Hydroiodic acid . .
Hydrogen ....
Hydrogen selenide .
Hydrogen sulphide .
Hydrogen telluride .
Krypton ....
Methane ....
Neon

Nitric oxide . . .
Nitrous oxide . . .
Nitrogen ....
atmospheric . .
Nitrogen dioxide
Nitrogen dioxide
Nitrosyl chloride
Oxvfiren

Phosphine ....
Propylene ....
Silicon fluoride . .
Sulphur dioxide . .
Xenon . .

* Quoted from Landolt-Bornstein. Phys.-Chem. Tabellen, 1905, p.
with revisions by Olsen.

222,

252

APPENDIX

V. — PHYSICAL CONSTANTS

[ Number j ]

Name

Sym-
bol

Atomic
Weight
O = 16

Molec-
ular
Weight

Specific
Gravity
Water =1
Air=l (A)
Hydrogen =
1 (D)

\tomic
Vol.
At.Wt.

Specific
Heat
at 0° C.

8p. Gr.

1

Aluminium . .

Al

27.1

2.5834°

10.5

.2220

2

Antimony . . .

Sb

120.2

6.62

18.2

.0495

8

Argon, gas . .

A

39.9

39.9

(1.379 A
I 19.96 D

.1233

4

liquid ....

A

39.9

1.4046-1860

28.5

5

Arsenic, amorph.

As

75.0

300

4.716140

15.9

.0758 { 21°-

6

cryst

As

75.0

300

5.727140

13.2

.0830 I 65°

7

Barium ....

Ba

137.4

3.75

36.7

8

Bismuth . . .

Bi

208.5

9.7474

21.4

.03013

9

Boron, amorph. .

B

11.0

2.45

4.5

.3066

10

cryst

B

11.0

2.53-2.68

4.2

11

Bromine, gas . .

Br2

79.96

159.92

5.869160° A

.0555(83°)

12

liquid. . . .

Br2

79.96

159.92

3.18830°

25

.1071

13

Cadmium . . .

Cd

112.4

112.4

8.64217°

13

.0548

14

Caesium ....

Cs

132.9

2.366

56

.04817

in

CalSium . . .

Ca

40.1

1.544629.20

26

.1804

1(5

Carbon, amorph.

C

12.00

1.75-2.10

6.0

.241

17

graphite . . .

C

12.00

2.10-2.585

5

.202

IS

diamond . . .

C

12.00

3.47-3.5585

3.4

.1469

19

Cerium ....

Ce

140.25

7.0424

20

.04479

20

Chlorine, gas . .

Cl

35.45

70.90

2.491°°A

.1241

21

liquid ....

Cl

35.45

1.44050°

24.6

.2262

22

Chromium . . .

Cr

52.1

6.9220

7.6

.10394

23

Cohalt . [bium)

Co

59.0

8.718H0

6.8

.1030

24

Columbium (Nio-

Cb

94.0

7.06i|°

13.3

25

Copper ....

Cu

63.6

8.91-8.96

7.1

.0936

21 i

Erbium ....

Er

166

4.77

34.8

27

Fluorine, gas . .

F

19

38

1.31i5°A

28

liquid ....

F

19

38

1.14-1870

16.7

2<>

Gadolinium . .

Gd

156

1.31

119.1

;io

Gallium . . .

Ga

70

5.9524°

11.8

.079

31

Germanium . .

Ge

72.5

5.469|§

13.3

.0737

:52

Glucinum (Beryl-

Gl

9.1

1.8520°A

4.9

x;

Gold . . [Hum)

Au

197.2

19.32

10.2

.0316

;u

Helium, gas . .

He

4

4

C 0.1368 A
1 1.98 D

*From Van Nost rand's Chemical Annual — Olsen.
f K = the number of grams of water which can be raised from 0° to 1° C.
by the heat which passes through a cubic centimeter of the substance in

APPENDIX

253

OF THE ELEMENTS*

Number

||?

Electrical
Conduc-
tivity
at 0° C.

Thermal
Conduc-
tivity
Kt at 0° C.
Ag- = 1.00

Linear
Coefficient of
Expansion

Melting
Point,

Boiling
Point,

1

6.02

324000

.3435

.042313

At°C.
40°

657°

1470-1700°

2

5.95

27100

.0442

.041152

40°

630°

1500-1700°

3

4.92

.043894

—187.9°

- 186.1°

4

6

5.69

28600

.040559

40°

<360°

6

6.23

sublimes at

449*°

7

850°

vol. 950°

8

6.28

9260

.0177

.041346

40°

269°

1435°

1)

3.37

infusible

sublimes at

10

infusible

3500°

11

4.44

12

8.57

-7.3°

59°

13

6.16

146000

.2213

.043069

40°

321.7°

778°

14

6.41

25400

.0339482

27-100°

26.37°

670°

15

7.23

95000

780-810°

16

2.89

.04054

40°

sublimes

3500°

17

2.22

.040786

40°

sublimes

3500°

18

1.76

.040118

40°

sublimes

3500°

19

6.28

623°

20

4.40

-102°

- 33.6°

21

8.02

•021978

0-10°

22

5.42

1515°

23

6.08

83200

.041236

40°

1530°

24

1950°

25

5.95

640600

.7198

.041678

40° {

1084°
1065°(inair)

2100°

27

— 223°

— 187°

28

— 223°

— 187°

29

30

5.53

30.15°

31

5.34

900°

vol. 1350°

32

>960°

33

6.23

468000

.7003

.041470

0-100°

1065°

34

.033386

< - 271.3°

-267°

one second when the temperatures of the opposite sides of the cube are
maintained at a difference of 1° C.

254

APPENDIX

Number ||

Name

Sym-
bol

Atomic
Weight
O = 16

Molec-
ular
Weight

Specific
Gravity
Water=l
Air=l (A)
Hydrogen =
1(D)

Atomic
Vol.
At.Wt.

Specific
Heat
at 0° C.

Sp. Gr.

1

Hydrogen, gas .

H

1.008

2.016

0.06949 A

3.410

2

liquid ....

H

1.008

2.016

0.700-252.60

1.4

6.

3

Indium ....

In

115

7.12?-

16.1

.05695

4

Iodine, gas . . .

I

126.97

8.72 A

.0336206°

K

solid .....

I

126.97

253.94

4.94817°

25.7

.05412

6

Iridium, spongy .

Ir

193.0

15.86

12.2

7

crystalline . .

Ir

193.0

22.42

8.6

.0323

8

Iron, pure . .

Fe

55.9

7.85-7.88

7.1

.1162

a

wrought . . .

Fe

55.9

7.86

7.1

.1130

10

steel ....

Fe

55.9

7.60-7.80

7.3

.1066

11

gray pig . . .

Fe

55.9

7.03-7.13

7.9

12

white pig . .

Fe

55.9

7.58-7.73

7.3

.1050

13

Krypton, gas . .

Kr

81.8

81.8

( 2.818 A
I 40.78 D

14

liquid ....

Kr

81.8

2.155-152°

37.9

15

Lanthanum . .

La

138.9

6.1545

22.6

.04485

K;

Lead

Pb

206.9

11.34

18.2

.0310

17

Lithium. . . .

Li

7.03

0.5936

12

.9408

IS

Magnesium . .

Mg

24.36

1.69-1.75

14.3

.2456

1!)

Manganese . .

Mn

55.0

7.42

7.4

.1217

20

Mercury . . .

Hg

200.0

200.00

13.59532

14.7

.03346

21

Molybdenum . .

Mo

96.0

8.6-9.01

10.9

.0659

22

Neodymium . .

Nd

143.6

6.9563

20.6

i:\

Neon

Ne

20

| 0.674 A

1 9.96 D

24

Nickel ....

Ni

58.7

8.6-8.93

6.7

.1084

25

Nitrogen, gas . .

N

14.04

28.08

0.96737 A

.2438

2<;

liquid ....

N

14.04

0.8042-195.50

17.5

27

Osmium . . .

Os

191

22.48

8.5

.03113

28

Oxygen, gas . .

0

16

32

1.10535 A

.2175

29

liquid ....

0

16

32

1.1181-182.5°

14.3

30

Ozone ....

03

48

1.658 A

31

Palladium . . .

Pd

106.5

11.4-11.9

9.2

.0592

32

Phosphorus, yel.

P

31

124

1.823220°

17.2

.202

33

red

P

31

124

2.11

14.7

.16981

34

liquid ....

P

31

1.76444.30

35

Platinum . . .

Pt

194.8

21. 481™*

9.2

.0323

3<>

Potassium . . .

K

39.15

0.87513°

44.7

.1662

37

Praseodymium .

Pr

140.5

6.4754

21.6

38

Radium ....

Ra

225

39

Rhodium . . .

Rh

103.0

12.1

8.5

.05803

40

Rubidium . . .

Rb

85.5

1.52215°

56.3

APPENDIX

255

| Number II

11*

Effi~

41-x

Electrical
Conduc-
tivity
at 0°"C. '

Thermal
Conduc-
tivity
Kt at 0° C.
Ag = 1.00

Linear
Coefficient of
Expansion

Melting
Point,
°C.

Boiling
Point,
°C.

1

3.44

.033270

At°C.

— 256.5°

- 252.5°

2

6.05

o

6.56

119500

.04417

40°

115°

red heat

4

4.27

5

6.86

.04837

-190-17

114.2°

184.35°

6

7

6.23

.040700

40°

1950°

8

6.50

131000

.1665

.041182

0°-100°

1804°

9

6.32

.2070

.0411

0°-100°

1600°

10

5.96

63000

.1300

.0411

0°-100°

1375°

11

{ 10200-

.041061

40°

1275°

1L>

5.87

(11300

.1490

1075°

13

— 169°

— 151.7°

14

15

6.23

810°

1(5

3.52

504CO

.0836

.042924

40°

327°

1400-1600°

17

6.62

119000

186°

>1400°

IS

5.98

230000

.3760

.042694

40°

632.6°

1100°

19

6.70

1245°

20

6.69

10630

.0148

.03182

0°-100°

— 38.85°

357.33°

21

6.33

22

840°

23

f 243° to

1 - 233°

24

6.36

144200 i

.1420

.041279

40°

1484°

25

3.42

.04524

— 210.5° (84

- 195.5°

2<;

[mm.)

27

5.95

105300

.040657

40°

2500°

28

3.48

.04563

< — 230°

— 182.5°

29

30

decomp. 270°

-119°

31

6.30

97900

.1683

.041176

40°

1535-1586°

32

6.26

.03124

0°-44°

44.2°

290°

33

5.26

350° (yel.)

34

35

6.29

91200

.1664

.040899

40°

1710-1780°

36

6.51

150500

.0483

0°-50°

62.5°

757.5°

37

940°

38

39

5.97

.040850

40°

1650-2000°

40

38.5°

696°

f See note on p. 252.

256

APPENDIX

| Nnmber 1 1

Name

Sym-
bol

Atomic
Weight
0 16

Molec-
ular

Weight

Specific
Gravity-
Water = 1
Air = l (A)
Hydrogen =

Atomic
Vol.
At.Wt.

Specific
Heat
at 0° C.

Sp. Qr.

1

Ruthenium, spon.

Ru

101.7

8.6

11.8

2

melted . . .

Ru

101.7

11.4

8.9

3

cryst

Ru

101.7

12.268°

8.3

.0611

4

Samarium . . .

Sm

150.3

7.7-7.8

19.4

5

Scandium . . .

Sc

44.1

6

Selenium, amorph.

Se

79.2

633.6

4.26-4.2825°

18.5

.09533

7

monoclinic . .

Se

79.2

633.6

4.4725°

17.7

.08401

8

hexagonal . .

Se

79.2

633.6

4.825°

16.5

(.)

Silicon, amorph.

Si

28.4

2.00

14.2

10

cryst

Si

28.4

2.49i°°

11.4

.169722°

11

Silver . . . .

Ag

107.93

10.53

10.2

.0559

12

Sodium ....

Na

23.05

0.973513.50

23.7

.2934

13

Strontium . . .

Sr

87.6

2.54

34.5

Sulphur,

14

amorphous soft

S

32.06

256.48

1.9556°°

16.4

15

" yellow

S

32.06

256.48

2.046

15.6

16

rhombic . . .

Sa

32.06

256.48

2.05-2.07°°

15.6

.163

17

monoclinic . .

S/3

32.06

256.48

1.958

16.4

18

plastic . . .

Sy

32.06

256.48

1.92

16.7

11)

Tantalum . . .

Ta

183

12.79

143

20

Tellurium, amorp.

Te

127.6

255.2

6.0152°°

21.2

21

cryst

Te

127.6

255.2

6.27

20.4

.0475

22

Terbium . . .

Tb

160

23

Thallium . . .

Tl

204.1

11.85

17.2

.0326

24

Thorium, amorph.

Th

232.5

11.0011°

21.1

2f>

cryst

Th

232.5

11.23

20.7

20

Thulium ....

Tm

171

27

Tin, gray . . .

Sn

119.0

5.846615°

20.3

.0545

28

rhombic . . .

Sn

119.0

6.53-6.56

18.2

.0559

2!)

tetragonal . .

Sn

119.0

7.298415°

16.3

.0559

30

Titanium . . .

Ti

48.1

3.543

13.6

.1125

31

Tungsten . . .

W

184

18.77

9.8

.0336

32

Uranium . . .

u

238.5

18.685V30

12.8

.0280

33

Vanadium . . .

V

51.2

5.8715°

8.7

.1153

34

Xenon, gas . .

Xe

128

| 4.422 A
1 63.5 D

35

liquid. . . .

Xe

128

3.52-109.10

49.1

36

Ytterbium . . .

Yb

173.0

37

Yttrium . . .

Yt

89.0

3.8015°

23.4

38

Zinc

Zn

65.4

7.14216°

9.2

.09356

3!)

Zirconium, amorp.

Zr

90.6

4.15

21.8

40

cryst

Zr

90.6

5.3

17.1

.0660

APPENDIX

257

i Number 1 1

*j* -

Electrical
Conduc-
tivity
at 0° Wt.

Thermal
Conduc-
tivity
Kt at 0° C.
Ag = 1.00

Linear
Coefficient of
Expansion

Melting
Point,

foiling
Point,

1

At ° C.

> 1950°

2

2000°

3

6.21

.040963

40°

2000°

4

5

6

7.55

50°

690°

7

6.65

.043680

40°

170°-18°

690°

8

217°

690°

g

3500°

10

4.82

200-15600

.040763

40°

1200°

3500°

11

6.04

681200

1.000

.041921

40°

961.5°

2050°

12

6.76

211000

.365

.0472

0°-50°

97.6°

877.5°

1.3

40300

900°

14

>120°

444.6°

15

444.6°

1(5

5.23

.046413

40°

114.5°

444.6°

17

119.25°

444.6°

18

444.6°

19

60600

.0408

2250°

20

.041675

40°

446°

1390°

21

6.07

46600

.043440

0°-20°

452°

1390°

22

23

6.65

56800

.043021

40°

301.7°

1600-1800°

24

25

27

6.49

stable <20°

28

6.65

stable >170°

29

6.65

76600

.1528

.042234

40°

232°

1450-1600°

30

5.41

3000°

31

6.18

1700°

32

6.68

800°

33

5.90

1680°

34

-1403

- 109.1°

35

37

38

6.12

186000

.2653

.042918

40°

419°

918°

39

1500°

40

5.98

t See note on p. 252.

258

APPENDIX

VI. — VOLUME AND WEIGHT OF WATER FROM 0° C. TO 31° C.*

Tempera-
ture

Volume of one
gram in c.c.

, Weight of one
c.c. in grams

Tempera-
ture

Volume of one
gram in c.c.

Weight of one
c.c. in grams

0°

1.000126

0.999874

16°

1.001025

0.998976

1

1.000070

0.999930

17

1.001193

0.998808

2

1.000030

0.999970

18

1.001373

0.998629

3

1.000007

0.999993

19

1.001564

0.998438

4

' 1.000000

1.000000

20

1.001768

0.998235

5

1.000008

0.999992

21

1.001981

0.998023

6

1.000031

0.999969

22

1.002204

0.997801

7

1.000069

0.999931

23

1.002438

0.997568

8

1.000122

0.999878

24

1.006781

0.997326

9

1.000188

0.999812

25

1.002935

0.997073

10

1.000269

0.999731

26

1.003199

0.996811

11

1.000363

0.999637

27

1.003472

0.996540

12

1.000470

0.999530

28

1 003788

0.996226

13

1.000590

0.999410

29

1.004045

0.995971

14

1.000722

0.999278

30

1.004346

0.995673

15

1.000867

0.999134

31

1.004656

0.995365

For the most recent results on the expansion of water,
which do not differ materially from the preceding, see An-
nalen d. Physik u. Chemie, [K R], 60, 340 (1897).
* Wied. Ann., 47, 400 (1892).

APPENDIX

259

VII. — VAPOR PRESSURE OF WATER FROM 0° C. TO 100° C.
IN MILLIMETERS OF MERCURY.*

Temp.

Pressure

Temp.

Pressure

Temp.

Pressure

Temp.

Pressure

0

4.569

25

23.517

50

91.98

75

288.76

1

4.909

26

24.956

51

96.66

76

301.09

2

5.272

27

26.471

52

101.55

77

313.85

3

5.658

28

28.065

53

106.65

78

327.05

4

6.069

29

29.744

54

111.97

79

340.73

5

6.507

30

31.51

55

117.52

80

354.87

6

6.972

31

33.37

56

123.29

81

369.51

7

7.466

32

35.32

57

129.31

82

384.64

8

7.991

33

37.37

58

135.58

83

400.29

9

8.548

34

39.52

59

142.10

84

416.47

10

9.140

35

41.78

60

148.88

85

433.19

11

9.767

36

44.16

61

155.95

86

450.47

12

10.432

37

46.65

62

163.29

87

468.32

13

11.137

38

49.26

63

170.02

88

486.76

14

11.884

39

52.00

64

178.86

89

505.81

15

12.674

40

54.87

65

187.10

90

525.47

16

13.510

41

57.87

66

195.67

91

545.77

17

14.395

42

61.02

67

204.56

92

566.71

18

15.330

43

64.31

68

213.79

93

588.83

19

16.319

44

67.76

69

223.37

94

610.64

20

17.363

45

71.36

70

233.31

95

633.66

21

18.466

46

75.13

71

243.62

96

657.40

22

19.630

47

79.07

72

254.30

97

681.88

23

20.858

48

83.19

73

265.38

98

707.13

24

22.152

49

87.49

74

276.87

99

733.16

* Taken from Ostwald's Manual of Physico-Chemical Measurements.

260

APPENDIX

VIII. —TABLE OF ELECTRO-CHEMICAL EQUIVALENTS

Table of Electro-chemical Equivalents based on the definition of the
ampere and the atomic weights, oxygen being 16

Element

Atomic Weight

Valency

Chemical
Equivalent

Electro-chemical
Equivalent
Grams pef
coulomb

Coulombs
per gram

(J rains per
ampere-hour

Ampere-hours
per pound

Electropositive

Aluniinum ....

27.11

3.

9.037

.00009362

10680.

.3370

1346.

Antimony ....

120.43

3.

40.14

.0004159

2405.

1.497

303.0

Bismuth

208.11

3.

69.37

.0007186

1392.

2.587

175.3

Cadmium ....

112.38

2.

56.19

.0005821

1718.

2.096

216.4

Cobalt

58.99

2.

29.5

.0003056

3272.

1.100

412.2

Copper (cuprous)

63.6

1.

63.6

.0006589

1518.

2.372

191.2

Copper (cupric) . .

63.6

2.

31.8

.0003295

3036.

1.186

382.4

Gold

197.23

3.

65.78

.0006815

1467.

2.453

184.7

Hydrogen ....

1.008

1.

1.008

.00001044

95785.

.03758

12070.

Iron (ferrous) . . .

56.02

2.

28.01

.0002902

3446.

1.045

434.0

Iron (ferric) . . .

56.02

3.

18.67

.0001934

5171.

.6962

651.5

Lead

20fi Q9

2.

103.5

.001072

932.8

3.859

117.5

Magnesium ....

^UO.r/^

24.28

2.

12.14

.0001258

7949.

.4528

1001.

Manganese ....

54.99

2.

27.50

.0002849

3510.

1.026

442.1

Mercury (mercurous)

200.

1.

200.

.002072

482.6

7.459

60.81

Mercury (mercuric) .

200.

2.

100.

.001036

965.3

3.730

121.6

Nickel

58.69

2.

29.35

.0003041

3288.

1.095

414.2

Platinum ....

194.89

4.

48.72

.0005047

1981.

1.817

249.6

Potassium ....

39.11

1.

39.11

.0004052

2468.

1.459

310.9

Silver

107 <¥>

1

107.92

.001118

894.5

4.025

112.7

Sodium

i\j ^ • *?£
23.05

1.

23.05

.0002388

4188.

.8597

527.6

Tin (stannous) . .

119.05

2.

59.52

.0006166

1622.

2.220

204.3

Tin (stannic) . . .

119.05

4.

29.76

.0003083

3243.

1.110

408.6

Zinc

65.41

2.

32.70

AAAOOOO

2952.

1.220

371.8

Electronegative

. UUUOOOo

Bromine •

79.95

j€

79.95

AAAQOQQ

1207.

2.982

152.1

Chlorine

35.45

1.

35.45

•vUUojJoO

.0003673

2723.

1.322

343.1

Iodine

126.85

1,

126.85

.001314

761.0

4.730

95.90

Nitrogen .

14.04

3.

4.68

.00004848

20627.

.1745

2599.

16.

2.

S.

.00008288

12066.

.2984

1520.

APPENDIX

261

IX.— TABLE SHOWING THE RELATIONS BETWEEN UNITS
OF ELECTRICITY, HEAT, AND POWER

1 ampere = 1 volt -r- 1 ohm.

" =1 coulomb per second.

1 ampere hour = 1 coulomb per sec-
ond kept up for
one hour.

1 ampere hour = 3600 coulombs.
1 volt = 1 ampere X 1 ohm.
1 ohm = 1 volt -4- 1 ampere.

1 joule = 1 volt x 1 coulomb.
" = .2381 calorie.

= .73732 foot-pound.
" = .10194 kilogram-meter.

1 calorie = 4.2 joules.

= 3.0968 foot-pounds.
" = .42815 kilogram-meter.

1 foot-pound = 1.3563 joules.
= .32292 calorie.
= .13825 kilogram-
meter.

1 kilogram-meter = 9.81 joules.

" =2.3362 calories.

= 7.233 foot-
pounds.

1 watt-hour = 1 watt kept up for
one hour.

1 watt-hour — • 1 joule per second
kept up for one
hour.

1 watt-hour = 3600 joules.

= 857.16 calories.
= 2654.4 foot-pounds.
= 366.98 kilogram-me-
ters.

1 watt = 1 joule per second.
" = .2381 calorie per second.
= .73732 foot-pound per sec-
ond.

1 watt = .10194 kilogram-meter per
second.

1 watt = .0013406 horse-power.
" = .001 kilowatt.

1 horse-power = 745.94 watts.

= 177.6 calories per
second.

1 horse-power* = 10656 calories per
minute.

1 horse-power = 550 foot-pounds per
second.

1 horse-power = 33000 foot-pounds
per minute.

1 horse-power = 76.04 kilogram,
meters per sec-
ond.

1 horse-power = 4562.4 kilogram-
meters per min-
ute.

1 horse-power = .74594 kilowatt.

1 kilowatt = 1000 watts.

" = 1000 joules per second.
". = 238.1 calories per sec-
ond.

1 kilowatt = 14286 calories
minute.

per

1 kilowatt = 737.32 foot-pounds per
second.

1 kilowatt = 44239 foot-pounds per
minute.

1 kilowatt = 101.94 kilogram-me-
ters per second.

1 kilowatt --= 6116.4 kilogram-me-
ters per minute.

1 kilowatt = 1.3406 horse-power.

262

APPENDIX

X. — HEATS OF COMBINATION

Heats of Combination in Calories, for Equivalent Weights in Grams,
of Chlorides, Bromides, Iodides, Sulphate, and Nitrates *

Element

Valence

Chloride

Bromide

Iodide

Sulphate

Nitrate

Aluminium . .

3

53660

39900

23463

25315

Antimony . . .

3

30463

Bismuth

3

30210

Cadmium .

2

46620

37600

24215

44940

43000

Cobalt ....

2

38240

44350

42270

Copper ....

1

32875

24985

16260

Copper ....

2

27980

26205

Gold ....

3

7607

2950

Hydrogen . . .

1

39315

28380

13170

39170

33830

Iron

2

41025

46600

44835

Lead ....

2

41385

32225

19900

34035

Magnesium . .

2

75505

90090

88240

Manganese . .

2

55995

60625

58860

Mercury . . .

2

31580

17155

18535

Nickel ....

2

37265

43475

41710

Silver ....

1

29380

22700

13800

10195

8390

Tin ....

2

40395

Zinc

2

48605

37965

24615

53045

51255

* These values are taken from Thomsen's Thermo-chemische Unter-
suchungen. The sulphates, nitrates, and hydrogen compounds are for
aqueous solutions. The chorides, bromides, and iodides are anhydrous.

APPENDIX 263

XL — SPECIFIC RESISTANCE OF VARIOUS SUBSTANCES

Substance

Temperature

j*>

J

1

GO

p
in Ohms

% Solution

Observer

0°C.

10 6

.000001500

Matthiesen

10.6

.000001530

M

89

.000001594

i

Copper (hard drawn) ....
Gold (annealed)
Gold (hard drawn)
Aluminium (annealed) . . .
Platinum (annealed) ....

II

8.9
19.3
19.3
2.6
21.2
8.1

.000001629
.000002052
.000002089
.000002903
.000009030
.000009687

'

Tin (pressed) . .

II

7 3

00001317

t

Zinc (pressed) . .

«

71

.000005598

4

Lead (pressed)

II

11.4

.00001957

4

Nickel (pressed)

M

8.5

00001242

j

German silver . .

II

about .0000209

4

Graphite . . .

((

2 3

0024 to .042

Everett

Retort carbon

II

1 9

07

Mercury

M

13 6

000094073*

Nitric acid in water

18° C.

1.185

1.28 t

29.7

Kohlrausch

Hydrochloric acid in water . .
Sulphuric acid in water . . .
Phosphoric acid in water . . .
Tartaric acid in water ....
Acetic acid in water ....
Ammonium chloride in water .
Sodium chloride in water . .
Sodium sulphate in water . .
Zinc sulphate in water . . .
Zinc sulphate in water . . .
Copper sulphate in water . . .
Potassium sulphate in water
Potassium bichromate in water-

n'

10° C.

1.092
1.224
1.307
1.107
1.022

1.270
1.422
1.205

1.31 f
1.36 t
4.79 t
9.97 t
61.9 t
2.5 t
4.7 t
11.3 t
28.5 t
33.7 J
29.3 $
16.6 $
29,6 J

18.3
80.4
46.8
22.4
16.6

Kohlrausch
and
) Nippoldt

Ewing
and
Macgregor.

Further data on the conductivity of the solutions can be found in
Physikalisch-Chemische Tabellen, Landolt and Bornstein, pp. 103,
106.

Kohlrausch and Nippoldt, Pogg. Ann., 138, p. 379 (1869).

Grotrian Pogg. Ann., 151, p. 378 (1874).

Kohlrausch and Grotrian, Pogg. Ann., 159, p. 233 (1876); and
Wied. Ann., 6, p. 145 (1879).

* From the definition of the ohm.
t Solution of minimum resistance. J Saturated solution.

264

APPENDIX

XII. — DENSITIES OF VARIOUS SUBSTANCES

The following table gives the weight in grams of 1 cc. of
the substance. These densities are but approximate.

Acetic acid 1.064

Agate 2.615

Alcohol, absolute . . . 0.796
Alcohol, methyl . . . .0.796

Alum 1.724

Aluminium 2.670

Amber 1.078

Antimony, cast .... 6.720
Apple-tree wood .... 0.790

Arsenic ' . . 8.310

Ash, dry 0.690

Ash, green 0.760

Asphalt 2.500

Basalt 2.950

Beech, dry ... 0.690 to 0.800

Beeswax 0.964

Bell-metal 8.050

Benzine .... 0.72 to 0.740

Benzole 0.884

Birch 0.690

Bismuth, cast 9.822

Blood 1.060

Boxwood 1.280

Brass, cast 8.400

Brass, sheet 8.440

Brick 1.6 to 2.000

Bromine 3.187

Butter 0.942

Calcium chloride . . .. 2.230

Camphor 0.988

Carbon disulphide . . . 1.272
Carbon dioxide, liquid . . 0.947
Cedar, American .... 0.554

Chalk 1.8 to 2.800

Cherry-tree 0.710

Chestnut 0.606

Chloroform. . 1.500

Clay 1.920

Coal, anthracite . 1.26 to 1.800
Coal, bituminous . 1.27 to 1.423

Cobalt 8.800

Concrete, ordinary . . . 1.900
Concrete, in cement . . . 2.200

Cork 0.240

Copper, cast 8.830

Copper, sheet 8.878

Deal, Norway 0.689

Diamond 3.530

Earth .... 1.52 to 2.000

Ebony 1.187

Elder 0.690

Elm 0.579

Elm, Canadian .... 0.725

Emerald 2.770

Emery 3.900

Ether 0.720

Feldspar 2.600

Fir, spruce 0.512

Fluorspar 3.200

Galena 7.580

German silver 8.432

Glass, flint . . . . 3.0 to 3.600

Glass, crown 2.520

Glass, plate 2.760

Glycerine 1.260

Gold 19.360

Gypsum, crys 2.310

Granite 2.650

Graphite 2.500

Gun-metal 8.561

Gutta-percha 0.966

Heavy-spar 4.430

Honey ....... 1.450

Human body 0.890

APPENDIX

265

XII.— DENSITIES OF VARIOUS SUBSTANCES —Continued

Hydrochloric acid, aq. sol. 1.222

Ice 0.917

Iceland spar 2.723

Iron, bar 7.788

Iron, cast 7.230

Iron, wrought 7.780

India-rubber 0.930

Iodine 4.950

Iron pyrites 5.000

Ivory 1.820

Lard 0.947

Lead, cast 11.360

Lead, sheet .... 11.400

Lignum vitse 1.333

Lime, quick 0.843

Limestone 3.180

Logwood 0.913

Magnesium 1.750

Mahogany . . . 0.56 to 0.852

Maple 0.755

Marble 2.720

Mercury 13.596

Milk -. . 1.032

Molasses 1.426

Mortar, average .... 1.700

Naphtha 0.848

Nitric acid . . . 1.38 to 1.559
Oak, American red . . . 0.850
Oak, American white . . 0.779
Oak, live, seasoned . . . 1.068
Oak, live, green .... 1.260

Oil, castor 0.970

Oil, linseed 0.940

Oil, olive 0.915

Oil, turpentine .... 0.870

Oil, whale 0.923

Paraffin . . . 0.824 to 0.940
Petroleum . . 0.836

Phosphorus . .
Pear-tree . . .
Pine, red, dry . .
Pine, white, dry .
Pine, yellow, dry .

. 1,830
. 0.660
. 0.590
. 0.554
. 0.461

Pine, pitch 0.660

Pitch . . . 1.150

Platinum wire .... 21.531

Poplar, common .... 0.389

Porcelain, china .... 2.380

Potassium 0.865

Quartz 2.650

Rock salt 2.257

Saltpeter . . . . . .2.100

Sand, quartz 2.750

Sand, river 1.880

Sand, fine 1.520

Sand, coarse 1.510

Silver, cast . . 10.424 to 10.511

Slate 2.880

Sodium 0.970

Steel, unhammered . . . 7.816

Sugar, cane 1.593

Sulphur, native .... 2.033

Sulphuric acid 1.840

Tallow 0.940

Tar 1.015

Tin, cast 7.290

Tourmaline, green . . . 3.150

Vinegar 1.026

Water, at 100° C. . . . 0.958

Walnut 0.680

Water, sea 1.027

Wax, white 0.970

White metal, Babbitt . . 7.310

Willow . 0.585

Zinc, cast 7.000

266 APPENDIX

XIII. — TABLE OF SOLUBILITIES*

Showing the classes to which the compounds of the commonly
occurring elements belong in respect to their solubility in water,
hydrochloric acid, nitric acid, or aqua regia.

Preliminary JRemarks

For the sake of brevity, the classes to which the compounds
belong are expressed by letters, as follows :

W or w, soluble in water.

A or a, insoluble in water, but soluble in hydrochloric acid,
nitric acid, or in aqua regia.

I or i, insoluble in water, hydrochloric acid, or nitric acid.

Further, substances standing on the border lines are in-
dicated as follows :

W-A or w-a, difficultly soluble in water, but soluble in
hydrochloric acid or nitric acid.

W-I or w-i, difficultly soluble in water, the solubility not
being greatly increased by the addition of acids.

A-I or a-i, insoluble in water, difficultly soluble in acids.

If the behavior of a compound to hydrochloric and nitric
acids is essentially different, this is stated in the notes.

Capital letters indicate common substances used in the
arts and in medicine, while the small letters are used for
those less commonly occurring. The salts are generally con-
sidered as normal, but basic and acid salts, as well as double
salts, in case they are important in medicine or in the arts,
are referred to in the notes. The small numbers in the
table refer to notes on the following pages.

Notes to Table of Solubilities

1. Potassium dichromate, W.

2. Potassium borotartrate, W.

3. Hydrogen potassium oxalate, W.

4. Hydrogen potassium carbonate, W.

* Taken from Wells' translation of the 16th German edition of Fresenius'
Qualitative Analysis.

APPENDIX

267

SOLUBILITY TABLE

Potassium

Sodium

Ammonium

Barium

Strontium

Calcium

Magnesium

Aluminium

Oxide ....

W

W

W

W

w

W-A

A

A

Chromate . . .

W,

w

w

a

w-a

w-a

w

Sulphate . . .

^13.15

W

"Wt4 20-30

I

I

W-I

W

W13.M

Phosphate . .

W

W8

W8-12

a

a

Au

aJ2

a

Borate ....

W2

*•

W

a

a

a

w-a

a

Oxalate . . .

W3

W

W

a

a

A

a

a

Fluoride . . .

W

w

W

w-a

w-a

A-I

a-i

w

Carbonate . .

W4

W10

W

A

A

A

A

Silicate ....

W

w

a

a

a

a

a-i

Chloride . . .

W37

^35

W21.38

W

W

W

W

w

Brotnid.6 ,

Hf\f\if\a

W

W

1OU1U6 ....

Cyanide . . .

W

W

w

\v-a

w

w

w

Ferrocyanide

W

w

w

w-a

w

w

w

Ferricyanide . .

W

w

w

w

w

Thiocyanate . .

W

w

W

w

w

w

w

Sulphide . . .

W

W

W

W

w

W-A 45

a

a

Nitrate . . .

W

W

W

W

W

w

w

w

Chlorate . . .

W

w

w

w

W

w

w

w

Tartrate . . .

WB.6. 7. 22 46

W7

^6

a

a

A

w-a

w

Citrate ....

W

w

W

a

a

w-a

w

w

Malate ....

W

w

W

w&a

w

w-a47

w

w

Succinate . . .

w

w

w

w-a

w-a

w-a

w

w-a

Benzoate . . .

W

w

w

w

w

w

Salicylate . . .

w

W

W

w-a

w-a

w-a

w

Acetate . . .

W

W

W

W

w

W

w

W

Formate . . .

w

w

w

w

w

w

w

w

Arsenite . . .

W

w

w

a

a

a

a

Arsenate . . .

W

W

w

a

a

a

a

a

5. Hydrogen potassium tartrate, W.

6. Ammonium potassium tartrate, W.

7. Sodium potassium tartrate, W.

8. Ammonium sodium phosphate, W.

9. Acid sodium borate, W.

10. Hydrogen sodium carbonate, W.

11. Tricalcium phosphate, A.

12. Ammonium magnesium phosphate, A.

13. Potassium aluminium sulphate, W.

268 APPENDIX

SOLUBILITY TABLE — Continued

Cromium

|

55

Manganese

•3

i

g

1

O

Ferrous

B

•E

£

1
co

,

Mercurous

Oxide

A&I

A

a!7

A

A

a

A

a

AM

A

Chromate ....

a

w

w

a

a

w

a

A-I

a

Sulphate ....

W&I]5

W

W

W

W

w*,

W

W-A

A-I

w-a

Phosphate . . .

a

a

a

a

a

a

A

a

a

a

Borate

a

a

a

a

a

a

a

a

a

Oxalate ....

w-a

a

w-a

a

a

a

8

a

a

a

Fluoride ....

w

w-a

a

w-a

w-a

w-a

w

w

a

Carbonate ....

A

A

A

A

A

a

A

a

Silicate . .

a

a

a

a

a

a

a

a

Chloride ....

W&I

W

W

W

W

W

w«

I

W-I

A-I

Bromide ....

w&i

w

w

w

w

w

w

i

w-i

a-i

Iodide . . .

W

w

<f

w

w

W

w

i

W-A

A

Cyanide ....

a

A

a

a-i

a-i

a-i

I

a

Ferrocyanide . .

A-I

a

i

i

i

I

i

a

Ferricyanide . .

a

i

i

i

I

w

i

w-a

Thiocyanate . . .

w

W

w

w

w

w

w

i

a

A

Sulphide ....

a-i

AH

A

Ha

«19

A

a

•*

A

A

Nitrate ....

W

w

w

w

W

w

w

W

W

w»

Chlorate ....

w

w

w

w

w

w

w

w

w

w

Tartrate ....

w

a

w-a

a

w

w-a

W22

a

a

w-a

Citrate

w

w-a

a

w

w

w

W

a

a

a

Malate

w

w

W

w— a

w-a

a

Succinate ....

w-a

w

w

w-a

w-a

a

a

a

a

Benzoate ....

w

w

a

w-a

a

a

Sa'licylate ....

w-a

w-a

Acetate ....

w

W

w

w

w

w

W

w

W2,

w-a

Formate ....

w

w

w

w

w

w

W

w

w-a

w

Arsenite ....

a

a

a

a

a

a

a

a

Arsenate ....

a

a

a

a

a

a

a

a

a

a

14. Ammonium aluminium sulphate, W.

15. Potassium chromium sulphate, W.

16. Zinc sulphide, as a sphalerite, soluble in nitric acid,
with separation of sulphur ; in hydrochloric acid only upon
heating.

17. Manganese dioxide, easily soluble in hydrochloric
acid ; insoluble in nitric acid.

18. Nickel sulphide is rather easily decomposed by nitric
acid ; very difficultly by hydrochloric acid.

APPENDIX

269

SOLUBILITY TABLE — Concluded

Mercuric

•|

0

^3
3

5

Cadmium

•

2
o
O

Platinum

Stannous

Stannic

Antimonious

Oxide

A

A

a

a

a

a&i

AM

Chromate . . .

w-a

W

a

a

•"42

a

Sulphate ....

w,7

Wao

W

W

w

w

a

Phosphate . . .

a

a

a

a

a

w-a

Borate ....

a

w-a

a

Oxalate ....

a

a

a

w

a

w

a

Fluoride ....

w-a

a

W

w-a

w

w

w

Carbonate . . .

a

A

a

a

Silicate ....

a

a

Chloride .....

W28

W

W-Agg

W

WSH

W37-38

W

W40

W-A «

Bromide ....

w

w

w-a

W

w

W

w-a

Iodide

A

W

a

W

a

j

w

w

w— a

Cyanide ....

W

a

a

W

W

Ferrocyanide . .

1

w-a

i

i

Ferricyanide . .

i

Thiocyanate . .

w

a

a

w

Sulphide . . .

Aw

•«

a

A '

&3C

a39

*41

a41

A M.45

Nitrate . . .

W

W

W*

w

W

Chlorate . . .

W

w

w

w

W

Tartrate . . .

a

W

a

w— a

a

1*46

Citrate . . .

w-a

W

a

Malate . . .

w-a

w

w

w

Succinate . .

w-a

w

w

a

Benzoate . .

w-a

a

w

Salicylate . .

w

Acetate . . .

w

WM

w

w

w

w

Formate . . .

w

w

w

w

w

Arsenite . . .

a

A

a

Arsenate . . .

a

a

a

a

a

19. Cobalt sulphide, like nickel sulphide.

20. Ammonium ferrous sulphate, W.

21. Ammonium ferric chloride, W.

22. Potassium ferric tartrate, W.

23. Silver sulphide, only soluble in nitric acid.

24. Minium is converted by hydrochloric acid into lead
chloride ; by nitric acid into soluble lead nitrate and brown
lead peroxide which is insoluble in nitric acid.

25. Tribasic lead acetate, W.

270 APPENDIX

26. Mercurius solubilis Ifahnemanni, A.

27. Basic mercuric sulphate, A.

28. Mercuric amido-chloride, A.

29. Mercuric sulphide, ijot soluble in hydrochloric acid,
nor in nitric a,cid, but soluble in aqua regia upon heating.

30. Ammonium cupric sulphate, W.

31. Copper sulphide is decomposed with difficulty by
hydrochloric acid, but easily by nitric acid.

32. Basic cupric acetate, partially soluble in water, and
completely in acids.

33. Basic bismuth chloride, A.

34. Basic bismuth nitrate, A.

35. Sodium auric chloride, W.

36. Gold sulphide is not dissolved by hydrochloric acid,
nor by nitric acid, but it is dissolved by hot aqua regia.

37. Potassium chlorplatinate, W-I.

38. Ammonium chlorplatinate, W-I.

39. Platinum sulphide is not attacked by hydrochloric
acid, is but slightly attacked by boiling nitric acid (if it has
been precipitated hot), but is dissolved by hot aqua regia.

40. Ammonium stannic chloride, W.

41. Stannous sulphide and stannic sulphide are decom-
posed and dissolved by hot hydrochloric acid, and are con-
verted by nitric acid into oxide, which is insoluble in an
excess of nitric acid. Sublimed stannic sulphide is dis-
solved only by hot aqua regia.

42. Antimonious oxide, soluble in hydrochloric acid, not
in nitric acid

43. Basic antimonious chloride, A.

44. Antimony sulphide is completely dissolved by hydro-
chloric acid, especially upon heating; it is decomposed by
nitric acid, but dissolved only to a slight degree.

45. Calcium antimony sulphide, W-A.

46. Potassium antimony tartrate, W.

47. Hydrogen calcium malate, W.

APPENDIX 271

XIV.— SOLUTIONS*
Acids

Cone. HCl, sp. gr. 1.2, 39 % HCl by weight.

Dil. HCl, 3 N, sp. gr. 1.05, 10 % HCl by weight.

Cone. HNOS, sp. gr. 1.42, 70 % HN03 by weight.

Dil HN03, 3 N, sp. gr. 1.10, 10 % HN03 by weight.

Cone. H2SOt, sp. gr. 1.84, 98% H2S04.

Dil. H.2$04, 3 N, sp. gr. 1.09, 13% H2S04.

Cone. HF, 40%.

Acetic Acid, 2 N, 120 g. of glacial acetic acid in 1 liter.

Tartaric Acid, 2 N, 150 g. in 1 liter.

Aqua Regia, 1 part of cone. HN03 to 3 parts cone. HCl ;
to be prepared only when needed.

H2S gas is prepared by the action of HCl (1 : 1) on FeS ;
the gas should be washed by passing it through water before
using.

Bases

Cone. Ammonia, sp. gr. 0.90, 28 %

Dil Ammonia, sp. gr. 0.96, 10 % NH3.

Sodium hydroxide, NaOH, 4 N.

As the material used for qualitative purposes contains
about 10 % of water, the amount needed for a 4 N solution
will be 4 x 40 x -V° = 177.7 g. in 1 liter.

Potassium hydroxide, KOH, 4 N.

The grade used for analytical purposes contains about
20 % water ; hence the quantity needed for a 4 N solution
will be 4 x 56 x | = 280 g. in 1 liter.

Barium hydroxide, Ba(OH)2, saturated solution.

Calcium hydroxide, Ca(OH)2, saturated solution.

* Taken from Baskerville and Curtman's Qualitative Analysis, New
York, 1910.

272 APPENDIX

Salts

Ammonium acetate, NH4C2H302. Add 1000 cc. of am-
monium hydroxide (sp. gr. 0.90), slowly and with constant
stirring, to 1250 cc. of glacial acetic acid.

Ammonium carbonate, (NH4)2C03S04 free. Dissolve, with-
out heating, 192 g. of the powdered salt in a mixture of
80 cc. of NH4OH (sp. gr. 0.90) and 500 cc. of water. When
solution is complete, dilute to 1 liter. The strength is ap-
proximately 4 N.

Ammonium chloride, NH4C1, 4 N. 214 g. in 1 liter.

Ammonium motybdate solution. To a mixture of 271 cc.
of cold distilled water and 144 cc. of NH4OH (sp. gr. 0.90),
add 100 g. Mo03 and stir till solution is complete ; slowly
add this solution with constant stirring to a mixture of 489
cc. HN03 (sp. gr. 1.42) and 1148 cc. of water. Allow the
mixture to stand for 24 hours and then decant the clear
liquid into a bottle.

Ammonium oxalate, (NH4)2C204 • H20. 35.54 g. in 1 liter.

Ammonium sulphide (colorless), (NH4)2S. Saturate 3
parts of NH4OH with H2S, add 2 parts of ammonium hydrox-
ide, and dilute with an equal volume of water.

Ammonium sulphide (yellow), (1ST H^S.,.. Digest the color-
less undiluted (NH4)2S with flowers of sulphur in the pro-
portion of 1 g. to the liter and then dilute with an equal
volume of water.

Ammonium sulphate, (NH4)2S04, N. 100 g. in 1 liter.

Barium chloride, BaCl2 • 2 H20, N. 122.17 g. in 1 liter.

Bromine water, saturated solution.

Calicum chloride, CaCl2, anhydrous, N. 55.6 g. in 1 liter.

Calcium sulphate, CaS04 - 2 H20, saturated solution.

Chlorine water, saturated solution.

Cobalt nitrate, Co (N03)2 • 6 H20, for confirmatory tests for
Al and Zn. 0.5 g. in 1 liter.

APPENDIX 273

Ferric alum, Fe2(S04)3 • (NH4)2S04 - 24 H2O, saturated
solution.

Ferric chloride, FeCl3 • 6 H20,* 2 N. 180 g. in 1 liter.

Ferrous sulphate, FeS04 • 7 H20. To be prepared in small
amounts as needed.

Hydroclilorplatinic acid, H2PtCl6 • 6 H20. 10 % solution.

Hydrogen dioxide, 3%.

Lead acetate, Pb(C2H302)2 • 3 H20,f N. 189.5 g. in 1 liter.

Magnesia mixture. Dissolve 110 g. of MgCl2 • 6 H20 and
280 g. of NH4C1 in a liter of distilled water ; when solution
is complete, add 261 cc. of ammonium hydroxide (sp. gr.
0.90), then add enough water to make the volume 2 liters.

Mercuric chloride, HgCl2- Saturated solution.

Potassium acetate, KC2H302. Saturated solution.

Potassium chromate, K2Cr04. N. 97.3 g. in 1 liter.

Potassium cyanide, KCN, N. 65.2 g. in 1 liter.

Potassium dichromate, K2Cr207, N. 73.8 g. in 1 liter.

Potassium ferrocyanide, K4Fe(CN)6, N. 105.7 g. in 1 liter.

T^T

Potassium iodide, KI, — • 83.1 g. in 1 liter.
J

Potassium nitrate. KN02. 500 g. in 1 liter.

Potassium permanganate, KMn04, N. 79.1 g. in 1 liter.

Potassium thiocyanate, KCNS, N. 97.2 g. in 1 liter.

Silver nitrate, AgN03, — • 42.5 g. in 1 liter.

Silver sulphate, Ag S04. Saturated solution.

Sodium acetate, NaC2H302, 4 N. 328 g. in 1 liter.

Sodium carbonate, Na2C03 (dry). Saturated solution.

Sodium cobaltic nitrite, Na3Co(]Sr02)6. Dissolve 100 g.
KaN02 in 300 cc. distilled water, slightly acidify with acetic
acid, and then add 10 g. of Co(N03)2 • 6 H20. Allow the
solution to stand for 24 hours and filter if necessary. As
the solution does not keep very well, only small amounts
should be prepared at a time.

* Should contain a little free HC1. t The solution should contain some
free acetic acid.

274 APPENDIX

Sodium nitroprusside, Na2FeNO(CN)5 - 2 H20. 10 % solu-
tion.

Sodium phosphate, Na2HP04 - 12 H20, N. 119 g. in 1 liter.

Sodium stannite, prepared as needed by adding to a little
SnCl2 solution sufficient NaOH solution to redissolve the
precipitate which first forms.

Sodium thiosulphate, Na2S2O3 • 5 H20, N. 124 g. in 1 liter.

Stannic chloride, SnCl4, -^ 32.7 g. in 1 liter.
Stannous chloride* SnCl2 • 2 H20, ?• 56.5 g. in 1 liter.

a

Stannous chloride (for Bettendorff Test). Dissolve 113 g.
of SnCl2 • 2 H2O in 75 cc. of cone. HC1, and add a few pieces
of C. P. tin foil and keep in glass stoppered bottle.

Starch paste. Prepared as needed by mixing about 1 g. of
powdered starch with a little cold water to form a thin paste
and then adding it to 200 cc. of boiling water ; boil for a
minute, cool, and use. The solution does not keep, owing to
the growth of molds. It may be kept for some time, how-
ever, if a preservative such as CS2 is added.

* Should contain a little free HC1.

APPENDIX

275

XV. — TABLE EMPLOYED IN THE PREPARATION OF
STANDARD STOCK SOLUTIONS*

Quantity of

a»
s
g

Substance

Formular
Weight

Solubility
of Salt in
100 Pts. of
Cold Water

Per Cent
Metal

Salt to be
dissolved in
1 Liter to
give Strength
Ice. =100 ing.

0

of Metal

I

AffNOo

170

V. S.f

63.5

157

HgN03.H20 . . .

280

sol. in pres. of
HN03

71.5

140

Pb(N08)2 ....

331

48

62.5

160

Pb(C2H3O2)2-3H2O.

379

46

54.6

183

II

Hg(N08)2.J(H20) .

333

sol. in pres. of
HN03

60

167

HffClo

271

7.4

74

135J

Bi(N03)3 • 5 H20 . .

484

sol. in pres. of
HNOS

43

233

Cu(N03)2 • 6 H20 .

295

V. S.

21.5

465

CuCl2 • 2 H20 . . .

170

120

37

270

CuSo4 . 5 H2O . . .

249

40

25

400

Cd(NO3)2.4H2O. .

308

v. s.

36

278

CdCl2.2H20 . . .

219

140

51

196

3CdSO4-8H20 . .

769

v. s.

43.5

230

AS2O3

198

4.

75.5

( )5

Na2HAsO3 ....

170

V. S.

44

V Ji

227

Na2HAsO4 -'12 H2O .

402

28

18.7

( )ir

As205

230

150

65

153

SbCl3

226

sol. in pres. of

53

188

HC1

SnCl2-2H20 . . .

225

V. S.

53

189

SnCl4-5H2O . . .

350

V. S.

34

294

SnCl4

260

V. S.

46

218

* Taken from Baskerville and Curtman's Qualitative Chemical Analysis,
New York, 1910.

t Very soluble.

\ This amount readily dissolves in 1 liter of water containing .50 g. of
NaCl.

§ 33 g. in 1 liter HC1 (1 : 1) gives strength 1 cc. = 25 mg. As.
IT 267 g. in 1 liter will give strength 1 cc. = 50 mg. As.

276

APPENDIX

XV. — TABLE EMPLOYED IN THE PREPARATION OF
STANDARD STOCK SOLUTIONS — Continued

Quantity of

Q,

3

Substance

Forrnular
Weight

Solubility
of Salt in
100 Pts. of
Cold Water

Per Cent
Metal

Salt to be
dissolved in
1 Liter to
give Strength
Ice. = 1(10 mg.

o

of Metal

III

A1.2(S04)3.18H20 .

666

107

8.1

( )»

A1C13-6H20 . .

242

74

11.1

( )t

A1(N03)3.8H20. .

261

v. s.

10.3

970

Cr2(S04)3 • 18 H20 .

716

v. s.

14.6

690

K2Cr2(S04)4-24H20

1000

20

5.2

( )t

Cr(N03)3.9H20. .

400

V. S.

13

770

CrCl3-6H2O . . .

206.5

v. s.

19.6

570

FeS04-7H20 . . .

278

60

20

500

Fe(N03)3.9H20 .

404

v. s.

14

715

FeCl3-6H2O . . .

270

V. S.

20.7

482

Ni(N03)2-6H20. .

291

50

20

500

NiCl2-6H2O . . .

238

V. S.

25

400

NiS04 • 7 H2O . . .

280

106

21

475

Co(NO3)2-6H2O. .

291

V. S.

20

500

CoCl2-6H2O . . .

238

V. S.

245

407

CoSO4-7H20. . .

281

50

21

475

MnS04.4H20 . .

223

123

25

400

MnCl2-4H20 . .

198

150

28

360

Mn(NO3)2-<>H2O .

287

v. s.

19

527

ZnSO4-7H2O. . .

288

135

22.5

445

Zn(N03)2.OH20 .

298

V. S.

22

455

ZriCl2

136

v. s.

48

208

IV

BaCl2.2H2O . . .

244

41

56

179

Ba(C2H302)2 • H20 .

273

63

50

200

Sr(N0302)2 . 4 H20 .

284

40

31

324

Sr(NO3)2 ....

212

39

41.3

242

SrCl2-6H2O . . .

266

106

33

304

CaCl2

111

v. s.

36

278

Ca(N03)2 • 4 H20 .

236

V. S.

17

590

*620 g. in 1 liter will give strength 1 cc. = 50 mg. Al.
1 450 g. in 1 liter will give strength 1 cc. = 50 mg. Al.
j; 192 g. in 1 liter will give strength 1 cc. «= 10 mg. of Cr.

APPENDIX

277

XV. — TABLE EMPLOYED IN THE PREPARATION OF
STANDARD STOCK SOLUTIONS— Conceded

Quantity of

CM

3
0

Substance

Formular
Weight

Solubility
of Salt in
100 Pts. of
Cold Water

Per Cent.
Metal

Salt to 'be
dissolved in
1 Liter to
give Strength
Ice. = 100 rag.

0

of Metal

V

MgS04 • 7 H20 . .

246

77

9.7

( )»

Mg(N03)2 • 6 H20 .

256.5

200

9.4

1060

MgCl2 • 6 H20 . . .

203.5

365

11.9

837

NaCl .

58

35

40

250

Na2HPO4-12H2O .

358

9.3

13

( )t

NaNOj

85

80

27

371

KC1

75

32

52

192

KHSO4

136

v. s.

28.5

350

KN03

101

31

39

257

NH4C1

53

33

34

294

(NH4)2S04 ....

132

76

27.5

365

NH4NO3 ....

80

200

22.5

445

(NH4)2HP04 . . .

132

36.5

27.5

365

LiCl

42

80

16.7

600

LiNOg

69

48

10

( )t

* 515 g. in 1 liter will give strength 1 cc. = 50 mg. Mg.
t 77 g. in 1 liter will give strength 1 cc. = 10 mg. Na.
J 500 g. in 1 liter will give strength 1 cc. = 50 mg. Li.

278

APPENDIX

XVI.— COMPARISON OF CALCULATED AND OBSERVED
DECOMPOSITION VOLTAGES OF VARIOUS AQUEOUS
SOLUTIONS

Chloride

Bromide

Iodide

Sulphate

Nitrate

Calculated

1

Calculated

1

Calculated

Observed

Calculated

TS

•

1

O

Calculated

1
o

1.98

Magnesium . .
Zinc

3.28
2 11

31
2.11
1.9

1.65
1.63

2.56

1.79
1.58

1.07
1.06

2.01
1.25
1.12

3.91
2.31
1.95

2.35
2.03

3.83
2.23
1.87

Cadmium . . .

2.03

Aluminium .

2.33

2.0

1.74

1.53

1.02

.88

1.10

Iron

1.78

1.6

1.30

.68

2.03

1.95

Cobalt ....

1.66

1.43

1.05

.51

1.91

1.92

1.84

Nickel. . . .
Tin

1.62
1.76
1.80

1.33
1.61
1.63

1.40

.85
1.30
1.33

.87

.36
.71

.83

1.89

2.09

1.81
1.48

1.52

Lead ....

Copper ....
Silver ....

143

1.28

1.32
1.11

1.09
.99

1.02
.95

.71
.60

.64
.65

1.22
.44

1.14
.365

.36*

Antimony . .
Bismuth .

1.32
1.31

1.22
1.21

.80
.92

.44
.43

Hydrogen . .

1.71

1.31

1.23

.94

.57

.52

1.70

1.67

1.81

1.69

The observed decomposition values of the acids given
under hydrogen, together with many of the sulphates and
nitrates, are taken from LeBlanc's Electro-Chemistry, pp.
247-248. The other observed values are from Crocker,
Trans. Am. Inst. E. E., 1885, p 281.
* Experiment.

421 n