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EW QUESTIONS AND
iLEMS IN CHEMISTRY

UNIVERSITY OF CALIFORNIA
AT LOS ANGELES

GIFT OF

HERMAN FLECK

REVIEW QUESTIONS AND
PROBLEMS IN CHEMISTRY

COMPILED BY

M. S. H. UNGER, A.M.

HEADMASTER OK ST. JOHNS SCHOOL, MANL1US, NEW YORK

GINN AND COMPANY

BOSTON • NKW VoKK • CHICAGO • ]X)NDON

U5/Y

PREFACE

The fact is borne out by the experience of every teacher
J who has classes to prepare for college examinations, that the
^ contents of the prevailing textbooks fail to furnish adequate
%> scientific material and drill to pass the entrance examina-
tions. The subject is so broad and the theories involved are so
\ complex, that the student often finds himself on the thresh-
N} old of the examination room completely bewildered by the
' many facts, theories, laws, and details, and is entirely unable
, to make a scientific application of his knowledge.

This book has been prepared as a review of the theories
N, and laws of elementary chemistry, and there has been added
3 to each topic a sufficient number of problems to make a
"3 thorough application of the student's knowledge. It pre-
^ sumes on the student's part a thorough acquaintance with
\ physical mixtures, laws of densities and specific gravity, laws
^ of heat and electricity, the metric system, and an adequate
| training in some good textbook in elementary chemistry.

These questions and problems have been taken from the

^> most recent college, College Board, and Regents of the State

of New York examinations, and from the latest and most

^authoritative textbooks, and will be found from the author's

^experience more than sufficient to prepare a student for the

^entrance examinations for any college, or for the College

x Board examinations.

The questions and problems are classified so that a chapter
or parts of one may be taken up, in connection with the text-
book used in the class, for clinching the principles studied,
or the book may be used as a pre-examination review. It is
iii

iv REVIEW QUESTIONS AND PROBLEMS

not necessary that the student should solve all the prob-
lems, but such selection should be made as will assure the
instructor that he is adequately prepared.

It must be observed in the use of the book that the
student must seek much necessary information from his
text, and there should be accessible several good textbooks
for handy reference.

Eeference to the appendixes will be found helpful in
solving many of the problems.

Acknowledgment is hereby made to the authors and pub-
lishers of the following textbooks, for the material obtained
from their publications : Lee's " Experimental Chemistry,"
P. Blakiston's Son & Co. ; Linebarger's " Chemistry," Rand,
McNally & Company ; Newell's " Inorganic Chemistry "
and Baskerville and Estabrooke's " Problems in Chemistry,"
D. C. Heath & Co. ; Brownlee and Others' " First Principles
of Chemistry," Allyn and Bacon ; Morgan and Ly man's
" Chemistry," The Macmillan Company ; McPherson and
Henderson's "Elementary Chemistry" and the publications
of the College Entrance Examination Board, Ginn and Com-
pany ; and to the authorities of the various universities, and
to the Board of Regents of the State of New York, whose
entrance examination questions have been used.

MAKLIUB, NKW YORK M- & H. UNGER

CONTENTS

CHAPTER

PAGE

PHYSICAL DEFINITIONS

II.

CHEMICAL DEFINITIONS

III.

PHYSICAL LAWS AND THEORY

IV.

CHEMICAL LAWS

CHEMICAL THEORY

VI.

CHEMICAL DIVISION-

VII.

El ECTROLYTIC DlSSOCI \TION

VIII.

VALENCY

IX.

PERIODIC CLASSIFICATION

. 18

HYDROGEN AND WATER

. 19

XI.

THE NITROGFN GROUP AND AIR

XII.

THE OXYGEN-SULPHUR GROUP

. 29

XIII.

THE CVRHON Sn ICON GROUP

XIV.

Tin: HALOGENS

XV. TllE Al.KAI.INE-EARTH METALS ...... 45

XVI. TIIE ALKALI METALS ......... 49

XVII. Tin: ALUMINUM-BORON GROUP ...... 52

XVIII. THE IRON, NICKEL, COIIALT, PLATINUM GROUP. 55

XIX. THE COPPER, SILVER, GOLD GROUP .... 57

XX. THE CHROMIUM-MANGANESE GROUP .... 60

XXI. ORGANIC ACIDS AND COMPOUNDS ..... 62

XXII. K(,M ATID.NS AND GENERAL FORMULAS. ... 64

XXI 1 1. (^ r LSI KINS AND CALCULATIONS:

A. PERCENTAGE COMPOSITION ...... 74-

B. ATOMIC AND MOLECULAR WEIGHTS . . 75

C. SIMPLEST FORMULAS ... ..... 77

D. MOLECULAR FORMULAS ....... 78

XXIV. WEIGHTS AND VOLUMES FROM EQUATIONS . . 81

XXV. MISCELLANEOUS QUESTIONS AND PROBLEMS. . 85
XXVI. PROP.LEMS ON MEASUREMENT, TEMPERATI I:K,

WEIGHT, AND DENSITY ........ !»7

XXVII. APPENDIX . , 103

REVIEW QUESTIONS
AND PROBLEMS IN CHEMISTRY

CHAPTER I
PHYSICAL DEFINITIONS

1. Define physical change and give two examples.

2. Define matter and energy, density, specific gravity.

3. Define element, mixture, compound, molecule, atom,
electron, ion, gas.

4. What are properties ? Mention those common to all
matter. If we had no senses, would we know anything
about the properties of substances ?

5. What forms of energy are possessed by a clock ? a
projectile ? a trolley car ?

6. When a certain amount of water freezes, does it absorb
or give off heat ? What difference in heat transfer takes
place when water drops in temperature from 2° to 1°, and
from 1° to 0° ?

7. Give examples of physical changes which are pro-
duced through the agency of heat ; of light ; of electricity ;
of chemical changes.

8. Define the difference between a mixture and a com-
pound, and illustrate each.

9. Give examples of gaseous mechanical mixtures and
of gaseous chemical compounds. Give similar examples,
liquid and solid, and point out the most important differ-
ence between compounds and mixtures.

2 REVIEW QUESTIONS AND PROBLEMS

CHAPTER II
CHEMICAL DEFINITIONS

1. How does chemistry differ from physics ? What is
a chemical change ?

2. Define oxidation, reduction, kindling temperature,
decay.

3. How does combustion differ from decay and from
oxidation ?

4. What is a formula ? a reaction ? an equation ? a
radical ?

5. What is a flame ? What causes luminosity ? Why is
a Bunsen flame nonluminous ?

6. Define catalysis, molecule, electrolyte, nascent state,
allotropy.

7. Define deliquescence, efflorescence, electrolysis, and
illustrate each.

8. Define chemism, vapor density, isomerism, polym-
erism, absolute temperature.

9. Define hydroxide, alkali, metathetic reaction, solution.

10. Distinguish between crystals and water of crystalli-
zation ; between colloids and crystalloids ; between crystal-
line and amorphous.

11. Explain and illustrate deflagration, supersaturation,
fusion, sublimation.

12. What is meant by bivalent, monatomic, diatomic ?

13. State the meaning of distillation, filtrate, titration,
standard solution, indicator, neutral reaction.

14. Define the following terms: atom, valence, equivalent,
gram molecule, fermentation,.precipitation.

CHEMICAL DEFINITIONS 3

15. Give three methods for collecting gases, and the con-
ditions under which each may be advantageously employed.

1 6. To what classes of changes do the following belong :
(<y) the melting of ice ? (//) souring of milk ? (c) explosion
of gunpowder? (rl) corrosion of metals? (e) burning of a
candle ? (/) ringing of a bell ? (f/) stretching of rubber ?
(7i) boiling of an egg ? (i) dissolving of sugar ? (j) decay
of meat ? (k) magnetizing of a nail ?

17. What is the property that distinguishes compounds
from mixtures ? What is an element ? What conditions
must be taken into account in measuring the volumes of
gases ? By what instruments are these conditions meas-
ured '.' (Jive the laws which express the effect of these
conditions.

18. Distinguish between chemical and physical properties ;
between elements, compounds, and mechanical mixtures ;
between metals and nonmetals ; between gases, liquids, and
solids ; between oxidation and reduction.

19. In the measurement of volumes of gases what do you
mean by standard conditions ? Should you consider it neces-
sary to make use of such conditions in measuring volumes
of liquids or solids ? Why ?

20. Describe two ways in which well-formed crystals are
obtained. How should you distinguish a crystalline from an
amorphous body ?

21. Explain the object of each of the following processes
and how each accomplishes the end in view : (a) evapora-
tion of a solution of a solid ; (b) filtration ; (<•) distillation ;
((/) pulverization before dissolving ; (e) sublimation.

22. Name two forms of energy that may produce chemical
changes, and give an example of a change caused by each.

23. Define each of the following and give an example of
each : («) monobasic acid ; (lij dibasic acid ; (c) tribasic acid,

4 REVIEW QUESTIONS AND PROBLEMS

and write the name and the formula of a salt formed from
each of the acids mentioned.

24. Define spontaneous combustion and explain the
phenomenon.

25. Define and illustrate molecular weight, anhydride,
deliquescence, antiseptic, precipitate, monad, occlusion.

26. Define and illustrate the following : binary com-
pounds, hydrate, base, dyad, compound radical, metal, neg-
ative element.

27. Define chemical change ; classify the different kinds
of chemical change, and give an example of each.

28. Define basic anhydride, acid anhydride, and give an
example of each. What is a dibasic acid ?

CHAPTER III
PHYSICAL LAWS AND THEORY

1. State and illustrate the relation that exists between
centigrade, Fahrenheit, and absolute-temperature scales.

2. State the formulas for converting temperatures.

3. Explain the meaning of the following statement :
" A gas is under standard conditions of temperature and
pressure."

4. State (a) Boyle's (Mariotte's) Law; (ft) the Law of
Charles.

5. Distinguish between and illustrate (a) law, (ft) theory,
(c) hypothesis.

6. What is (a) occlusion ? (ft) diffusion of gases ?
(c) spectrum analysis ?

7. What is. the kinetic theory of matter ?

CHEMICAL LAWS 5

8. Define specific gravity or relative density, and show
how you would determine the specific gravity of a gas, a
liquid, and a solid. If the specific gravity of marble is 2.75,
how much in grams would a cubic meter of marble weigh ?

9. Explain in terms of the kinetic molecular theory the
difference between solids, liquids, and gases.

CHAPTER IV
CHEMICAL LAWS

1. State and illustrate the Law of Definite Proportions.

2. State and illustrate the Law of Multiple Proportions.

3. State the Law of Dulong and Petit. What use is
made of it by chemists ?

4. State the Periodic Law. What three striking predic-
tions made by Mendeleeff have since been verified ?

5. What is the basis of the Mendeleeff classification?
What evidence have we that this is a natural system ? Dis-
cuss the properties of the elements in some natural family
in such a way as to show this apparent relation.

6. Give the law for the conservation of matter; of
energy.

7. Give Hess's Law of Constant Heat Summation.

8. State the Law of Electrochemical Equivalents; the
Law of Equivalent Proportions.

9. State Graham's Law of Diffusion and Transpiration.

10. State the Law of Dal ton for a gaseous mixture.

11. What is the Law of Gay-Lussac ? Illustrate.

12. State Faraday's Laws of Electrolysis.

6 REVIEW QUESTIONS AND PROBLEMS

13. Name four agencies that may bring about a chemical
change, and illustrate.

14. State the Law of Specific Heats. Illustrate its use by
an example.

15. What are Berthollet's Laws ?

16. What distinction would you make between a law and
a theory ? Give an illustration of each and tell why it is
thus classified.

17. The formulas of the five oxids of nitrogen are N2O,
NO, N203, N204, and N2Og. What simple ratio exists between
the varying weights of oxygen ?

18. State and illustrate Ampere's Law. Mention a method
of finding the molecular weight of a given compound when
its atomic weights are not known.

19. State what is meant by saying that the vapor density
of a gas is 44.

20. State Boyle's Law and Charles's Law. A certain
quantity of a gas occupies 1 1. at 0° C. and 760 mm. Calculate
its volume at 20° C. and 750 mm.

21. State Avogadro's Law; also the Law of Multiple
Proportions. What volume of carbon dioxide would be
formed if 1 1. of acetylene (O^L^) burned in oxygen with
the formation of C02 and H2O ?

22. What is the law governing the combination of gases
by volume ? Give some examples illustrating the law. What
is the hypothesis advanced to explain it? Show how this
hypothesis gives rise to a method of expressing the weights
of molecules.

23. What evidence have we that matter is indestructible ?
If we cannot create matter, how are we to account for the
fact that the products of combustion of a candle weigh more
than the original caudle ?

CHEMICAL THEORY 7

24. Give and illustrate two laws that lie at the founda-
tion of clicniica.1 knowledge. What law gives the basis for
calculating molecular weight ?

25. Give the characteristics of a chemical change, and
two important laws governing chemical change.

CHAPTER V
CHEMICAL THEORY

1. State the principle of Dal ton's Atomic Theory.

2. State the theory of Avogadro, and illustrate it by
the union of oxygen and hydrogen to form water, and of
hydrogen and chlorine to form hydrochloric acid.

3. Explain the theory of electrolytic dissociation.

4. Show how Avogadro's theory is used for determining
molecular and atomic weights.

5. Employ the Avogadro theory in calculating the atomic
weight of oxygen from the following data : carbonic, acid
gas, steam, laughing gas, and sulphurous anhydride contain,
in the order named, 72.73, 88.89, 36.364, and 50.00 per cent
by weight of oxygen ; their densities are, in the same order,
22, 9, 22, and 32.

6. Tell what substance and how much of it, in terms of
the atomic-molecular theory, is represented by each of the
following symbols and formulas : HC1, Ba, Fe, P205, O2, Og,
KOH, Zn(N08)2, I, SiOa.

7. State Gay-hussar's Law of the combining volumes of
gases and show how it led to Avogadro's hypothesis.

8. What is meant by (V/) the molecular weight of a gas,
and (/>) the density of a gas ? What relation exists between
the molecular weights and the densities of gases ? Illustrate.

8 REVIEW QUESTIONS AND PROBLEMS

9. What evidence have we that one element can change
into another, and what explanation is offered ?

10. State the Law of (a) Definite Proportions ; (ft) Mul-
tiple Proportions. Show how the atomic hypothesis is
developed from these laws.

11. State Avogadro's hypothesis. Show how the molec-
ular weight of a given substance that can be volatilized may
be found by this hypothesis.

CHAPTER VI
CHEMICAL DIVISION

1. Define an acid, a base, and a salt, and give an example
of each.

2. Give the names of the following acids, and of the
potassium salt of each : HC1, HC10, HC1O4, HC103, HN02,
HN08, H2S04, HBr, H8As04, HF.

3. What is a formula, a chemical equation, a reaction, a
graphic equation ? Illustrate.

4. Illustrate an endothermic and an exothermic reaction.

5. Illustrate and explain the difference between ana-
lytic, synthetic, and metathetic reaction.

6. Define and illustrate neutralization, normal salt, acid
salt, basic salt, an anhydride.

7. Give an example of a dibasic acid. Of H2S04 acting
(a) as an acid ; (ft) as a drying agent ; (c) as a strong acid
displacing a weaker one (equation).

8. Classify as (a) bases ; (ft) acids ; (r) salts : NaNO,,
NH4C1, HC10, NH4OH, BaS04, Ca (NO,) 2, HC104, Sr(OH)2,
HN02, Fe(OH)8.

CIIK.MK AL DIVISION' 9

9. Write the formulas for the following compounds:

barium perclilorate. ammonium sulphate, strontium nitrate,
calcium sulphate, ferric sulphate, sodium perchlorate, cal-
cium hypochlorite, barium hydroxide, strontium oxide,
barium nitrate.

10. What is a primary salt? Write the formulas for
primary sodium sulphate, primary calcium phosphate,
secondary sodium carbonate.

11. How may hydrochloric acid be prepared? State the
properties of this acid.

12. Write the formulas for limestone, secondary sodium
phosphate, cupric sulphate, ammonia, aluminum phosphate,
mercurous chloride, barium nitrate, acetylene, gypsum,
marsh gas.

13. Write the formulas for sodium carbonate, lead sul-
phate, silica, arsine, arsenic trioxide, ammonium sulphide,
normal calcium phosphate.

14. Write the formulas for potassium chloride, sodium
carbonate, phosphoric acid, sodium cyanide, ferric oxide,
ferrous sulphide, ferric chloride, aluminum sulphate, cuprous
oxide, manganese dioxide.

15. Write the equation for the reactions that occur between

1. Potassium hydroxide and sulphuric acid.

2. Calcium hydroxide and ammonium sulphate.

3. Ferric chloride and ammonium hydroxide.

4. Sodium hydroxide and phosphoric acid.

5. Ammonium nitrate with heat.

17. Write the equations for the reactions between

1. Calcium carbonate and hydrochloric acid.

2. Potassium nitrate and sulphuric; acid.

10 REVIEW QUESTIONS AND PROBLEMS

3. Copper and water vapor (heated).

4. Aluminum sulphate and ammonium hydroxide.

5. Calcium carbide and water.

18. Write the equations for the reactions :

1. Silver nitrate and sodium chloride.

2. Aluminum sulphate and potassium hydroxide.

3. Ammonium sulphate and slaked lime.

4. Sodium chloride, manganese dioxide, and sulphuric

acid.

5. Chlorine and potassium bromide.

6. Steam and incandescent coke.

7. Calcium hydroxide and carbon dioxide.

8. Methane and oxygen (ignited).

19. What is meant by the terms " saturated solution " and
" supersaturated solution " ? Under what conditions will
crystalline sodium sulphate effloresce ?

20. For what do the following symbols and formulas
stand : S02, C, CH4, FeO, Fe208, CO2, CaC08, Hg, I,, H3P04,
NaOH, NH4, NH3, Ag, Al, 08, S6, AsOg, SnO2, and Pb(OH)2.

21. Define basic anhydride and acid anhydride, and give
an example of each.

22. Classify the following substances as (") acids, (/>) bases,
or (e) salts, and give the name of each : H2S04, KC1, KHS04,
NH4OC1, NaOH, CaF2, HI, Ca(C103)2, NaN03.

23. To what extent does the composition of a pure chemi-
cal compound vary ? Take as an example pure sodium
chloride from various sources, and mention other examples
if possible.

24. Give chemical names and molecular formulas for
the following substances : borax, Epsom salts, Glauber salts,
white vitriol, green vitriol, blue vitriol, iron pyrites, hematite,
magnetite, potash, galena, alum, gypsum, cryolite.

< IIKMICAL DIVISION 11

25. Complete and balance : •»

2. A1(OH)3

3. A.1(OH)8

4. AgNO, +

5. CaC08 + C02 + H/) =

26. Complete the following, using symbols and formulas :

1. Ammonium hydroxide + hydrochloric acid =

2. Ammonia + hydrochloric acid =

3. Sodium chloride + silver nitrate =

4. Ferrous sulphide + sulphuric acid =

5. Lead nitrate + hydrogen sulphide =

6. Manganese dioxide 4- hydrochloric acid =

7. Calcium carbide + water =

8. Arsenic trioxide + nascent hydrogen =

9. Sodium carbonate + nitric acid =

10. Calcium hydroxide + carbon dioxide =

27. Explain the terms "ion" and " ionization." What
classes of substances are ionized when dissolved in water ?
I '> y what term are all such substances designated ? De-
tiiit1 acid and base in terms of the theory of electrolytic

dissociation.

28. Explain by the ion theory the action of hydrochloric
;icid on potassium hydroxide iii dilute solution.

29. Classify the given compounds under the following
headings: (") acids; (7>) bases; (V) normal salts; (V) acid
salts; (,<) anhydrides; (/) oxides: CO.,, NaHSO4, CaCl2,
1'bO, II:JP04, Ca(OH)2, Na.2S08, Mi,o.,.~SO,, NaOCl.

30. Write the chemical name ol each of the following:

white lead, blue \itriol, calomel, gypsum, saltpeter, caustic
potash, copperas.

12 REVIEW QUESTIONS AND PROBLEMS

31. Distinguish in meaning between the following suffixes
when used in names of chemical compounds : (V/) <ms and ic ;
(f>) ite and ate. (c) When are hypo and per prefixed ?

32. Define each : (a) monobasic acid ; (b) dibasic acid ;
(V) tribasic acid. Write the name and the formula of a salt
formed from each of the acids mentioned.

33. Find the percentage composition of HNOg. Describe
a method -of preparing nitric acid, writing the reaction.
Mention its uses.

34. What substances do you employ in the laboratory
preparation of hydrochloric acid ? Why was each substance
selected ? Give the reason for the method used.

35. Write the chemical name of each of the following :
H2S08, NaHC08, H2S, Fe (S04)3, P205.

36. Complete the following equations, using formulas :

1. Sodium hydroxide + carbon dioxide =

2. Lead nitrate + hydrogen sulphide =

3. Calcium hydroxide + nitric acid =

4. Phosphorus + oxygen =

5. Sodium carbonate + calcium chloride =

6. Hydrogen + (hot) copper oxide =

State which of these compounds are (</) acids ; (7;) bases ;
(r) salts ; (rf) anhydrides. Which of the equations are exam-
ples of (e) oxidation ? (/) reduction ? (^/) double decom-
position ? (//,) neutralization ?

37. State how you could distinguish between

1. Concentrated and dilute sulphuric acid.

2. Sodium chloride and sodium sulphate.

3. Copper sulphate and potassium sulphate.

4. Platinum and magnesium.

5. Pulverized charcoal and manganese dioxide.

6. Hydrogen and carbon monoxide.

CHEMICAL DIVISION 13

38. What determines whether a gas should be collected
(a) over water ? (ft) by downward displacement of air ?
(<•) by upward displacement of air ? State the method used
in collecting ammonia, hydrogen sulphide, carbon dioxide,
nitric oxide.

39. Describe two ways in which well-formed crystals are
obtained. How should you distinguish a crystalline from
an amorphous body ?

40. Explain each of the following processes, and state
how each accomplishes the end in view : («.) evaporation of
a solution of a solid ; (It) filtration ; (<••) distillation ; (<I) pul-
verization before dissolving ; (e) sublimation.

41. Describe experiments by which you could determine
whether

1. An alloy contained copper or silver.

2. A washing powder contained sodium carbonate.

3. A sample of potassium chlorate contained potas-

sium chloride.

4. A sample of material contained sand or lime.

5. A gas was nitrogen or carbon dioxide.

42. Distinguish between organic and inorganic chemistry ;

between metals and nonmetals.

43. Name the following acids and write the formula and
name Ihe sodium salt for each:

HI HNO3 H8PO2 H2S04

HIO, UNO, H8P08 H2S08

HI04 HNO H8P04 HaSaO8

44. When perfectly dry sulphuric acid is treated with
perfectly dry sodium hydroxide, no chemical action takes
place. Why?

45. What is a radical '.' (Jive six examples.

14 REVIEW QUESTIONS AND PROBLEMS

46. What are the main points of difference between
metals and nonmetals in the free state ? What chemical
property differentiates them as a rule ? Name some elements
which have properties of both.

47. Define acid and base. What is the important theo-
retical conception concerning solutions ? What is the mean-
ing of the terms " weak " and " strong " as applied to these
substances ? Define hydrolysis.

48. State the differences between the solutions obtained
by passing dry ammonia gas into water and sulphur dioxide
into water. What is the result if each solution is evaporated
separately? Explain. What is obtained when the solutions
are mixed and evaporated to dryness ?

49. What weight of Ca(OH).2 can be prepared from 1 kg.
of quick lime, and what weight of HC1 will be neutralized
by the Ca(OH)2 thus made ?

CHAPTER VII
ELECTROLYTIC DISSOCIATION

1. Describe in full what happens when a solution of
sodium sulphate is electrolyzed.

2. Describe in detail what takes place when an electric
current is passed through water that has been acidulated
with sulphuric acid.

3. Explain what takes place when a solution of copper
sulphate is electrolyzed with a copper cathode and ;i copper
anode. What commercial use is made of this process ? If
both terminals were platinum.

4. Explain the terms "ion" and " ioni/ation." What
classes of sul (stances are ioni/.ed when dissolved in water?

ELECTROLYTIC DISSOCIATION 15

1 5 y what term arc all such substances designated ? Define acid
and base in terms of the theory of electrolytic dissociation.

5. Explain by the ion theory the action of hydrochloric
acid on potassium hydroxide in dilute solution.

6. How would you determine whether a given solution
is an electrolyte ?

7. To bring about a reaction between dry substances,
why is it necessary to place them in water?

8. Distinguish carefully between an ion of sodium and
an atom of sodium.

9. Explain the fact that sulphuric acid is less active
than nitric acid.

10. Give the conditions under which a reaction goes on
to completion.

11. If a certain current of electricity deposits 31.7 g. of
copper, (« ) how much silver would it deposit ? (/>) how
much zinc?

12. From the standpoint of the theory of electrolytic disso-
ciation («) write the simple equation for a dilute solution of
copper sulphate ; this is a blue solution, (i) In the same man-
ner write one for sodium sulphate ; this is a colorless solu-
tion. How would you account for the color in the first case ?

13. Why will vegetables cook faster when boiled in strong
salt water than when boiled in pure water ?

14. Write equations showing how the following substances
ionize: HC1; HNOg; NaOH; Ca(OH)2; ZuS04; Fe(NO8)a.

15. Write ionic equations for the interactions of the fol-
lowing substances. Do the reactions run to equilibrium or
to completion ? Why in each case ?

1. NaOH + HC1 - 4. BaCl2 + Na2S04 -

2. Na3COs + HN03 - 5. Ca (OH)2 + H2SO4 -

3. Ca(OH)2 + HC1 - 6. AgNO, + HC1 -

16 REVIEW QUESTIONS AND PROBLEMS

16. Why do less volatile acids decompose the salts of
more volatile acids and liberate the latter?

17. Why does liquid chlorine possess no acid properties ?
Would you expect it to conduct an electric current ?

18. Salt dissolved in pure water conducts electricity;
sugar does not. Explain according to modern views.

19. Describe the changes undergone by a solution of
sodium sulphate (colored with litmus) when subjected to
the action of a current of electricity. How may the direc-
tion of the current be determined ?

20. Define the term " electrolysis." Explain briefly by
means of a diagram what takes place when an electric current
is passed through a solution of common salt.

21. Define dissociation. Describe a laboratory experiment
to illustrate the dissociation of a chemical compound by the
aid of electricity.

22. What important difference is there between the be-
havior of table salt and that of sugar when dissolved
in water ? How may the peculiar behavior of salt be
shown? Name some of the substances which behave in
this manner.

23. Define an ion and an electrolyte.

24. A current deposits 1 g. of sodium ; find the weight
of Ni deposited by the same current.

25. How many grams of Ag will be deposited from a solu-
tion of AgN08 by a current of 2 amperes in 30 minutes ?

26. How much would a metal plate increase in weight if
it were nickel-plated by a current of 0.5 ampere running
5 hours ?

27. If the specific resistance of Ca is 0.000001629, what
is the resistance of a wire 200 in. long having a cross section
of 2 mm.2 ?

VALENCY 17

28. Gladstone and Hibbert on passing the same electric
current through solutions of zinc and silver obtained quan-
tities of the metals in the ratio of (Zn) 1 : (Ag) 3.298. If
the equivalent of silver is 197.94, what is that of zinc ?

29. When sulphuretted hydrogen is added to a solution
of ZnS04, why is the zinc not completely precipitated as
sulphide ? How may the precipitation be made approxi-
mately complete? Explain by means of the hypothesis of
electrolytic dissociation and the law of mass action.

CHAPTER VIII
VALENCY

1. For what do the following symbols and formulas
sfciml: S02, C, CH4, Fe203, C02, CaC08, Hg, I2, HgP04,
Nat HI, (OH), (NHJ, NH8, Ag, Al, 08, S6, As208, Sn02, and
Pb(OH)2?

2. Complete and balance :

1. NaOH + H2S04 =

2. Mg + HCl =

3. Na + H2O =

4. NaN08+NH4Cl + H.E.=

5. NaCl + Mn02 + H2S04 + H.E.=
NOTE. H.E. stands for heat energy.

3. What is meant by saying that a chemical equation
" balances" ? Why is it incorrect if it does not " balance" ?

4. AVhat is valence ? What is the valence of iron in Fe08,
and of silicon in SiH4? What is meant by saying that an
element occurs in different allotropic forms ?

5. Define valence. State and illustrate the theory of
valence.

18 REVIEW QUESTIONS AND PROBLEMS

6. If 1 1. of bromine vapor weighs 7.2 g. and if 1 g. of H
combines with 80 g. of bromine, what is the valency of
bromine ?

7. The valency of the following elements is indicated by
the number of accents : Na', K', Ca", Al'". What are the
formulas of the chlorides and the oxides of each of the
elements if Cl is univalent and 0 is bivalent?

8. How many liters of hydrogen gas can be obtained
from 4 1. of HC1 acid gas ?

CHAPTER IX

PERIODIC LAW AND THE CLASSIFICATION OF THE
ELEMENTS

1. State the Periodic Law. What three striking predic-
tions made by Mendeleeff have since been verified ?

2. Discuss the periodic classification of the elements.
What evidence have we that this is a natural system ? -Dis-
cuss the properties of the elements in some natural family
in such a way as to show their apparent relation.

3. Name the important services the law (periodic) lias
rendered to chemistry.

4. What property of an element determines its position
in the periodic. arrangement of the elements?

5. Arrange the following elements in groups according
to some natural classification : aluminum, barium, iron,
phosphorus, silicon, sodium, sulphur.

6. What is the difference between the Periodic Law and
the Periodic System ?

7. State the characteristics of the alkali group; of the
halogen group; of the carbon group; of the argon group.

HYDROGEN AM) WATER 19

8. If lead is an element and radium is an element, what
is tin- most significant difference between them?

9. What reasons are there for thinking that there may
be only one form of matter ?

10. Suppose that an element were discovered that filled
the blank in Group VI, Period 9, Family 13 (see Appendix),
what properties would it have ?

CHAPTER X

HYDROGEN AM) WATER

1. (u) Give two physical and two chemical properties of
JL. (//) Name two metals which displace H from dilute HC1,
and two that do not.

2. State (Jay-hussar's Law of Volumes and illustrate it
by a consideration of the union of H and Cl. Show by
Avogadro's theory and the foregoing law that a molecule
of II contains at least two atoms.

3. What volume of H measured under standard con-
ditions is required to reduce 11.94 g. of CuO ? What is
the weight and what the volume of the water (liquid)
formed '.'

4. -> H2 + Oa= 2H20. What does this equation signify
in regard to (<y) molecules, (ft) the weights, and (c) the gas
volumes of the reacting substances and of the product ?

5. How many grams of the metal Zn are necessary for
the production, by the action of hydrochloric acid on the
metal, of 90 1. of H measured under standard conditions ?

6. 30 cc. of H is mixed with 40 cc. of air that contains
20 per cent of (), and the mixture is ignited. What gases
remain after explosion and what is the volume of each?

20 REVIEW QUESTIONS AXD PROBLEMS

7. When H and 0 unite, state the relation of the volume
of steam produced to the volumes of H and 0 used. State
the law thus illustrated.

8. A tube containing copper oxide (CuO) weighs with
its contents 63 g. This tube is heated to redness and H
passed through it. When cooled the tube with its contents
is again weighed, and the weight is now found to be 60 g.
\Vhat volume of H measured under standard conditions has
united with the 0 of the copper oxide ?

9. How may water be freed (a) from insoluble solid
matter ? (U) dissolved salts ? (c) dissolved air ?

10. Give the formulas of a compound of H and S and
of two oxides of sulphur. Show by equations how each of
these oxides of S would react with a water solution of
NaOH.

11. Give the volume relations between the gases in the
following reactions : hydrogen and chlorine combining to
form hydrochloric acid ; hydrogen and oxygen to form
steam ; hydrogen and nitrogen to form ammonia. If a
million molecules of H took part in each reaction, how
many molecules of each product would be formed ?

12. If to 36 g. of water at ordinary temperature we add
metallic sodium until no further reaction takes place, what
weight of H will be set free ? What volume will it occupy
at 18° and 740 mm. ? What proportions of the H originally
contained in the water will it constitute ? What weight
of Na will suffice ? How many gram-atoms of Na will
this be ? How many gram-molecular volumes will the H
occupy ?

13. Show how the composition of water may be deter-
mined by weight and by volume.

14. Distinguish between hard and soft waters. How are
lianl \\airrs sol'tcucd '.' I low do we obtain pure water?

HYDROGEN AND WATER 21

How does pure water at ordinary room temperature behave
when heated to 100° C. or cooled to 0° C. ?

15. Describe the process by which water may be decom-
posed by electrolysis, touching on apparatus generally used
and method of collecting the resulting gases. Name the
gases and give the test for each.

16. What is meant by a solution of a substance ? Describe
an experiment illustrating (a) saturated solution; (b) a
supersaturated solution.

17. Distinguish in composition between water of perma-
nent hardness and that of temporary hardness, and state
how each may be softened.

18. Dumas and Stas obtained the result of nineteen deter-
minations of the gravimetric composition of water to be an
average of 840.161 g. of 0 formed from 945.439 g. of water.
Calculate the ratio of combination.

19. If crystallized calcium sulphate contains about 18 per
cent of water, what volume of steam at 200° C. and 755 mm.
is given off by heating 100 g. of the solid until all the water
of crystallization is expelled ?

20. Calculate the volume of 1 g. of H under standard
conditions.

21. Iron and tin ores usually are oxides. In obtaining
the metals Avhat kind of reactions are used ?

22. What changes would take place in nature if water did
not expand (rr) when cooled below 4° C. ? (&) when it freezes ?

23. The gas density of water vapor is about 9. Calculate
the volume occupied by 1 g. of water when in the form of
si cam at 100°. When the steam is doubled in volume, to
what temperature would it have 1o l»e heated?

24. How could you determine the total amount of solid
material contained in a sample of water ?

22 REVIEW QUESTIONS AND PROBLEMS

25. How may it be ascertained by experiment that water
contains the elements hydrogen and oxygen and these two
elements only ?

26. What weight of H will be required for the complete
reduction of 10 g. of CuO ? At 740mm. and 15° C. what
will be the volume of the H ?

27. What is meant by " water of crystallization," and
what relation does it bear to the terms "efflorescence" and
" deliquescence " ?

28. Describe three methods of obtaining hydrogen by the
decomposition of water.

29. Describe the essential features of the " mechanical
nlethod " of water filtration.

30. How may impure water be rendered fit for drinking
purposes ?

31. How would you prove that the composition of water
is expressed by the formula H20 ?

32. A liter of H weighs 0.0899 g. A liter of oxygen
weighs 1.429 g. Explain the significance of the term "atomic
weight," and explain the calculation of the atomic weight
of 0 from the above data.

33. Describe an experiment illustrating the solubility of
ammonia in water.

34. One volume of oxygen at 80° C. will go to form how
many volumes of steam under the same conditions ? How
will the number of molecules of each compare ? What in-
ference can be drawn from the last answer as to the char-
acter of the 0 molecule ? How do we account for the
increase in the density when 0 is converted into ozone ?

35. To what constituent do acids owe their characteris-
tic properties? Does this substance impart these proper-
ties to all its compounds ? What is the theory advanced

HYDROGEN AND WATER 23

to explain the facts embraced in your answer ? How do we
explain the fact that some acids are stronger than others ?
Name some other facts which the above-mentioned theory
explains.

36. What weight of Zn would be required for the pro-
duction of sufficient H at 21° C. and 745 mm. pressure to fill
a balloon with a capacity of 100 cc. ?

37. Make a sketch of an apparatus employed for the
electrolysis of water; explain the process and state the
significance of the result.

38. State all that takes place when steam is passed over
heated iron. How may the gaseous product of the reaction
be identified ? Make a sketch of the apparatus which might
be used to carry out this experiment. Making use of the
solid product, outline an experiment to illustrate the pro-
duction of water.

39. How much sodium by its action upon water is required
to furnish 76 1. of H at 100° C. and 746 mm. ?

40. How may it be shown experimentally that ammonia
consists of H and N ?

41. What are hydrazine and hydrazoic acid ? Discuss their
properties.

42. 32.3 cc. of H at 18° C. and 744 mm. are introduced
into a eudiometer, 56.8 cc. of () at 20° C. and 745 mm. added.
Which gas and how much of it at 21° C. and 745 mm. will be
left after the explosion, if the tension of the aqueous vapor
produced be taken into account'.'

43. Show how the composition of water and of hydrogen
peroxide illustrate the Law of Multiple Proportions.

44. Would you use Zn or Fe for making H to fill a large
balloon? Why? Would H make; a good illuminating gas ?

45. Ts water an oxide? an anhvdride?

24 REVIEW QUESTIONS AND PROBLEMS

46. The density of Cl is nearly thirty-six times that of H.
Compare its rate of diffusion with that of H.

47. If the density of ice is .92, what volume will a liter
of water at 4° C. occupy when frozen ?

48. Give three reasons for considering that water is not
an elementary substance. Define the terms " element " and
" compound."

49. How many grams of H can be obtained by treat-
ing 30 g. of Zn with sulphuric acid, and what will be the
volume at 20° C. and 760 mm. ?

CHAPTER XI
NITROGEN GROUP AND AIR

1. How can ammonia be made from ammonium chloride ?
Write equations to show how ammonium hydroxide reacts
with nitric acid and aluminum chloride.

2. Calculate the volume that 10 1. of air at 25° C. would
occupy at 0° C.

3. Give the name and formula for the common nitrogen
:icid. From what is it usually made and how? Illustrate
the important chemical properties of the acid by equations
for its reactions with both zinc and zinc oxide.

4. Explain the fact that when strong nitric acid acts on
copper, red fumes are evolved. Illustrate your explanation
by equations.

5. Give the formulas for two common oxides of phos-
phorus ; also for two common oxides of arsenic. Write
the equations for reactions showing the formation of two
salts containing phosphorus, and of two salts containing
arsenic.

NITRO<;i:X (JROUP AND AIR 25

6. Show by equations the different effects of concen-
trated nitric acid on copper, cuprous oxide, and cupric oxide.

7. How do arsenic and antimony differ from the true
metals ?

8. Give the reaction equations for the preparation of
the following substances : ammonia, nitric acid, nitric oxide,
nitrous oxide, phosphorus.

9. What volume of ammonia gas, at a temperature of
20° C. and a pressure of 740 mm. of mercury, can be obtained
from 214 g. of sal ammoniac, and how should one proceed
to prepare it ?

10. Name and describe the elements of the nitrogen
family ; mention the group to which they belong and state
its general characteristics.

11. Give the sources, preparation, properties, and uses of
nitric acid.

12. Write the formulas of the potassium and ammonium
salts of sulphuric and nitric acids ; of nitrogen peroxide.

13. Why is it impossible to write a chemical formula
of air ? Why is a mixture of air with illuminating gas
explosive ?

14. Write the equations for («) the neutralization of potas-
sium hydroxide and nitric acid; (A) preparation of nitrogen
from sodium nitrite and ammonium chloride.

15. Give, with equation, a jnethod of preparation of
ammonia and state the properties of the substance.

16. Write the formula for primary ammonium phos-
phate, secondary potassium phosphate, ammonium sulphate,
calcium phosphate, sodium nitrate.

17. Write the names and formulas of the live oxides of
nitrogen. Give a brief statement of the important law
illustrated by these compounds.

26 REVIEW QUESTIONS AND PROBLEMS

18. What are the constituents of the atmosphere : («) per-
manent ? (b) variable ?

19. What weight of nitrous oxide will be formed when
80 g. of ammonium nitrate is decomposed by heat ? What
will be the volume of this nitrous oxide at 745 mm. pressure
and a temperature of 18° C. ?

20. Give the structural formulas of NH4CL, NH4OH,
and (NH4)2S04.

21. The formula of phosphoric acid is HgPO4. What is
the formula of primary sodium phosphate ? secondary am-
monium phosphate ? normal calcium phosphate ? secondary
calcium phosphate ?

22. The specific gravity of ammonia compared to H is
8.5. What is its molecular weight? Explain the steps by
which this result is reached.

23. Discuss the preparation of P as to equation and
method and describe its allotropic forms.

24. How is ammonia used in refrigeration ? Describe the
methods of preparation and the properties of liquid air.

25. From what material and by what process may white
phosphorus be made ? What are its properties and for what
is it used ? How may it be converted into red phosphorus ?

26. What is white arsenic ? How may arsenic be detected
in a case of suspected poisoning ?

27. Give two reasons for the belief that the nitrogen
and the oxygen in the atmosphere are mixed and not
combined.

28. In what great industry is calcium phosphate (normal)
employed? To what treatment must it he subjected? How
may free phosphorus be prepared ? What is its usual source?

29. Give the sources, method of preparation, and proper-
ties of the element nitrogen.

NITROGEN GROUP AND AIR 27

30. Give the equation for the reaction that takes place
when laughing gas is prepared. Make a sketch of the
apparatus used.

31. Give formulas and names of some compounds of
phosphorus, arsenic, and nitrogen, which are analogous in
their formulas and chemical behavior.

32. Which of the constituents of the atmosphere are
essential to animal life and which to plant life ? • What is
returned to the atmosphere by animals and what by plants ?
Give two reasons to show that these constituents of the
atmosphere are not in chemical combination.

33. What is the commercial source of ammonia? How is
it prepared (equation) and how may it be shown (a) that it
has the character of a base, (/>) is lighter than air, (c) and
is readily soluble in water ?

34. When N is prepared from the atmosphere what other
element does the gas contain ? Name two different ways in
which the salts of nitric acid may be prepared.

35. Compare the properties of the two common modifica-
tions of phosphorus. What is the formula of the product
of the combination of phosphorus in oxygen, and what name
is given to this compound which indicates its chemical
behavior ?

36. Name two metals which are not readily acted upon
by the atmosphere. For what purposes does this property
of these metals render them particularly serviceable ?

37. Name the compounds commonly used as the sources
of nitrogen, phosphorus, and potassium in commercial
fertilizer. How is the nitrogen of the air made available
f<>r plant food?

38. How could you show the presence of four substances
in the air ?

28 REVIEW QUESTIONS AND PROBLEMS

39. Write the graphic formula of arsenic trioxide. De-
scribe its preparation and mention its important properties
and uses.

40. Describe a method of preparing hydrogen arsenide.
Give equation. State the ordinary use of hydrogen arsenide.

41. Explain the instability of nitrogen compounds. De-
scribe an experiment illustrating this instability.

42. Describe a process of extracting the metal arsenic
from one of its ores. Mention the physical and chemical
properties of arsenic.

43. Describe in detail Marsh's test for arsenic and write
the reaction.

44. Two compounds have the following composition :
(«) phosphorus 56.36 per cent, oxygen 43.64 per cent;
(&) phosphorus 43.65 per cent, oxygen 56.35 per cent. Show
whether or not the Law of Multiple Proportion holds.

45. Give the name and compound formed («) when phos-
phorus burns in air ; (7/) when the product is treated with
water and the solution boiled. Write the equations for both
reactions.

46. Mention four gaseous components of the atmos-
phere and tell briefly how you .would demonstrate their
presence.

47. Describe the preparation of ammonium chloride as a
by-product in the manufacture of illuminating gas from
coal. Give the important uses of ammonium chloride.

48. Give the composition of ordinary gunpowder. Explain
the expansive force of ignited gunpowder and write the
reaction that takes place.

49. Give at least two reasons for the belief that the
oxygen and nitrogen of the atmosphere are not in chemical
combination.

OXYGEN-SULPHUR GROUP 29

50. What chemical changes are produced by the action of
lightning in the air ? Does atmospheric N differ from that
obtained from a compound ?

51. Name the members of the nitrogen family, tabulate
their resemblances and analogous compounds, and show how
that relation illustrates the basis of the natural classification
of the elements.

52. When ammonia and air are heated and passed over
the catalytic agent (spongy platinum) nitric acid is formed.
What does this prove as to the composition of nitric acid ?

53. What happens to nitric acid when passed through a
red-hot tube ? What is the effect of heat upon («) potassium
nitrate ? (f>) lead nitrate ? (c) ammonium nitrate ?

CHAPTER XII
OXYGEN-SULPHUR GROUP

1. What volume of oxygen, measured under standard
conditions, will be evolved when 198 g. of mercuric oxide
are decomposed by heating? What will be the volume of
the oxygen at 770 mm. pressure and 27° C. ?

2. When 2 g. of a certain substance were heated, all
the oxygen which the substance contained was given off
and the residue weighing 1.97 g. was left. Calculate the
percentage of oxygen in the substance.

3. Describe briefly experiments in the laboratory to illus-
trate the effect of heat on sulphur (the air excluded).

4. State briefly how you could distinguish between

1. Concentrated and dilute sulphuric acid.

2. Sodium chloride and sodium sulphate.

3. Copper sulphate and potassium sulphate.

30 REVIEW QUESTIONS AND PROBLEMS -

5. State what substances you would use to prepare :
(a) S02; (6)H2S; (c) CO ; (rf) CO2.

6. Describe how you would prepare S02 in the laboratory.
Give its physical and chemical properties. How may it be
converted into H2S04 ? How could you distinguish a solu-
tion of sulphurous acid from sulphuric acid ?

7. Name some of the chemical results which might be
expected if the atmosphere were composed entirely of 0.

8. How is hydrogen sulphide made ? Mention the im-
portant physical properties ; the chemical.

9. What is formed when a solution of sodium hydroxide
is saturated with hydrogen sulphide ?

10. What is the principal product when sulphur burns in
the air ? Give two physical properties of the compound
and show by equations how it reacts with water and with
two different oxidizing solutions.

11. Write the equations showing the reactions of dilute
sulphuric acid with the following substances : (a) sodium
sulphide ; (6) potassium carbonate ; (c) ammonium hydroxide ;
(d) cupric oxide ; (e) aluminum hydroxide ; (/) lead nitrate ;
(ff) barium chloride ; (A) zinc.

12. Give the formulas for the common oxides of phos-
phorus, calcium, copper, and silicon. Which of these oxides
unite readily with water ? Give the names and the formulas

*for the compounds so formed.

13. Calculate the volume of carbon dioxide at 20° C. and
750 mm. pressure that would be produced by burning 200 g.
in oxygen.

14. Write the formulas, and indicate whether basic or
acidic, of the oxides of the following elements : aluminum,
barium, iron, phosphorus, silicon, sodium, sulphur.

OXYGEN-SULPHUR GROUP 31

15. Show that the preparation of sulphur dioxide from a
sulphite is similar in principle to the preparation of hydrogen
sulphide.

16. Calculate the percentage composition of sulphur-
ous anhydride and sulphuric anhydride. Show how these
two substances are in harmony with the Law of Multiple
Proportions.

17. How many pounds of sulphur would be necessary in
the preparation of 100 Ib. of 90 per cent sulphuric acid ?

18. Write the names and formulas of the oxides and
oxygen acids of selenium and tellurium.

19. What weight of potassium chlorate is necessary to
prepare 200 1. of oxygen at 20° C. and 750 mm., and what is
its productive cost at .50 ct. per kilogram ?

20. How does a mixture of potassium chlorate and man-
ganese dioxide act when heated ? What gas is evolved ?
Is there interaction, and if not, what is such a process called ?

21. Distinguish between combustion, decay, oxidation,
and putrefaction.

22. Explain spontaneous combustion and give examples.

23. Compare the manufacture of sulphur with that of
charcoal.

24. Coal often contains iron pyrites. What sulphur com-
pounds do you think would be found in illuminating gas
made from such coal ?

25. How would you distinguish between a sulphide, a sul-
phite, and a sulphate ?

26. How much, both by weight and by volume, is re-
quired to burn 100 g. of S containing 12 per cent of incom-
bustible impurities ?

27. Describe the occurrence of sulphur in nature and state
the uses to which it is put.

32 REVIEW QUESTIONS AND PROBLEMS

28. State three ways of preparing S02 and tell how it is
converted into SOg.

29. With the aid of Avogadro's hypothesis calculate the
volume of oxygen that will be required for the complete
combustion of 10 1. of the following gases : (a) acetylene ;
(&) methane ; (c) ethane, C2H6 ; (d) ethylene, C2H4 ; (e) CO.
What volume of C02 will be formed in each case ?

30. How does ozone differ from oxygen ? How may
ozone be prepared ? What are its properties and uses ?
Give in full the properties of oxygen.

31. Give the properties of H2S04 and describe its prep-
aration by the " contact " process.

32. Give three methods for the preparation of oxygen and
explain what relation it bears to respiration and combustion.

33. How much H2S04 and zinc would be needed to fill
1100 balloons, each of a capacity of 2000 cc., with hydrogen
at a pressure of 1000 mm. of mercury ?

34. Describe (with sketches) two experiments by means
of which it may be shown that under certain conditions a
gas ordinarily spoken of as a supporter of combustion may
become a combustible.

35. Define oxidation and reduction and give two examples
of each. Describe three experiments to illustrate the differ-
ence between the properties of oxygen and atmospheric air.

36. The weight of a liter of O under standard conditions
is 1.429 g. What volume will 25 kg. of 0 occupy at a tem-
perature of 18° C. and a pressure of 740 mm. ?

37. What volume of a solution of H2S04 containing 196 g.
of the acid per liter will be required for the exact neutral-
ization of 100 cc. of a solution of NaOH containing 40 g. to
the liter ?

38. Give all possible uses of H2SO4.

OXYGEN-SULPHUR GROUP 33

39. Write equations showing the result of adding H2S04
to (a) iron ; (7>) quicklime ; (c) a solution of barium chloride.
What is the chemical change which takes place when
HaS04 is added to sugar?

40. Under what conditions is native sulphur usually
found ? Name two classes of sulphur compounds which
occur in nature.

41. How may S02 be prepared by (a) an oxidizing proc-
ess ? (&) by reduction ?

42. How many grams of copper sulphide can be formed
by burning 2 g. of copper in sulphur vapor ?

43. Explain the chemical difference in the bleaching
action of SO2 and Cl.

44. Describe («) the principal sources of sulphur in nature.
(l>) State one method of preparation, (c) Mention allotropic
forms.

45. Explain why the gaseous product produced by the
action of H2SO4 with copper differs from that usually pro-
duced by the action of an acid with a metal.

46. Give the proportions of 0 in normal air by weight
and by volume and describe a laboratory experiment to
show how each of these proportions are determined.

47. Describe an experiment showing the value of H2S as
a reducing agent. State the property of H2S to which its
value as a reducing agent is due.

48. Berzelius converted 10.000 g. of lead into 14.642 g.
of lead sulphate (PbSO4). The atomic weights of lead and of
oxygen are 206.91 and 16.00. Calculate the atomic weights
of sulphur.

49. Is the equation for the preparation of hydrosulphuric
acid a reversible one ? As ordinarily carried out, does it com-
plete itself ? Does dry hydrosulphuric acid react with litmus ?

34 REVIEW QUESTIONS AND PROBLEMS

60. In what respects is sulphurous acid like carbonic acid ?

51. How does a mixture of chlorate and manganese
dioxide act when heated ? Calculate the volume under
standard conditions and also the weight of the gas pro-
duced if 245 g. of chlorate are used.

52. Describe a method of preparing oxygen, describe its
properties, and relate the history of its discovery.

53. Describe the lead-chamber process for the manufacture
of H2S04.

54. Define combustion and kindling temperature. Give an
account of the discovery of oxygen and of the effect which
the study of its properties had upon the development of the
science of chemistry.

CHAPTER XIII
CARBON, SILICON, TIN, LEAD GROUP

1. Compare the composition, manner of formation, and
properties of the oxides of carbon, silicon, tin, and lead.

2. How do you account for a weak acid such as H2C03
being able to decompose such stable compounds as the sili-
cates, as illustrated by the weathering of rocks ?

3. A certain ore has 90 per cent galena. How much
pure lead can be obtained from a ton of the ore ?

4. If white lead were mixed with barium sulphate, how
could you detect the adulteration ?

5. What are hydrocarbons and where are they found ?
Mention three hydrocarbons present in illuminating gas.

6. Why does the air of a tightly closed room in which
lamps are burning become unfit to breathe ? What is the
explanation of the explosions which often occur in houses
when illuminating gas has been escaping ?

CARBON, SILICON, TIN, LEAD GROUP 35

7. What is the purpose in using baking soda in dough ?
Why does a lamp burn better with the chimney on than off ?

8. Describe the manufacture of white lead, giving equa-
tions and uses.

9. Discuss combustion, the nature of a flame, and the
factors which cause and modify the luminosity of a flame.

10. Describe fully the oxides of carbon and the ways
in which they are formed and prepared.

11. Point out the chemical similarity between carbon and
silicon.

12. Give (a) the equation for the combustion of carbon
monoxide in oxygen, (i) What will be the relative volumes
of the gases taking part in the reaction ? (c) What will be the
relative weights of the gases ? (d) If 56 g. of carbon monoxide
are used, what will be the volumes of oxygen required under
standard conditions ?

13. Calculate the volume occupied by 10 g. of carbon
dioxide at 27° C. and 38 cm. pressure, assuming that 1 g. of
C02 at 0° C. and 76 cm. occupies .509 1.

14. Calculate the weight of sodium hydroxide that would
react with 22.4 1. of C02 under normal conditions of tem-
perature and pressure, sodium hydroxide to be in excess.

15. State from personal experience how C02 was pre-
pared in the laboratory, and write the reaction involved.
State two properties of CO2 which were ascertained by
experiment. How may it be shown that C02 is one of the
products of respiration ?

16. What do you consider the most important compound
of (a) carbon ? (ft) silicon ? (c) tin ? (d) lead ? Why ?

17. How does the total weight of the products of com-
bustion of a candle compare with the total weight of the
materials taking part in the combustion ? Name and state
the law which this illustrates.

36 REVIEW QUESTIONS AND PROBLEMS

18. State a chemical method of distinguishing between
CO and C02 and describe a method by which each may be
converted into the other.

19. Name an important ore of lead. How would you
proceed to get metallic lead into solution ? Give the formula
of the resulting compounds of lead.

20. Name two natural and two artificial modifications of
the element carbon. What are the chief products resulting
from the heating of soft coal without access of air ? How
does coal gas differ chemically from water gas ? Under what
conditions does a combustible substance burn with a flame ?
Name two purposes for which graphite is commonly used.

21. Name the substances used in the manufacture of
glass. How does the composition of hard glass differ from
that of soft glass ?

22. How is water gas made ? What gases does it contain ?
Why is it carburetted (enriched) ? To what constituent is
the poisonous character chiefly due ?

23. Give the chemical name and the mineralogical name
of one important ore of lead. Describe briefly the mode of
extracting the metal, name two practical uses to which it is
put, and state what property renders it particularly suited
to each purpose named. What metals are components of
solder and brass ?

24. Discuss the chemical changes which take place in a
furnace fire, as follows :

1. What substances cause the blue flame at the surface

of the coal and how is it formed ?

2. State and give reasons for the effects of admitting

air (a) to the top of the fire ; (b) to the bottom.

3. How does anthracite coal differ from bituminous

in appearance and chemical quality ?

CARBON, SILICON, TIN, LEAD GROUP 37

25. Draw a vertical section (diagram of a candle flame),
showing its structure. Indicate on the diagram the part of
the flame having (a) greatest luminosity ; (6) greatest heat.

26. Find the weight of each of the products of combustion
when 78 g. of acetylene are burned.

27. Write in order the chemical name and the formula
of each of five members of the marsh-gas series.

28. Describe the process of fractional distillation of
petroleum. Mention three useful products derived from it,
with formulas.

29. Distinguish as to chemical composition and properties
between fire damp and choke damp and explain why each
is dangerous in mines.

30. Describe in detail a process of manufacturing lead
carbonate on a commercial scale. State the principal use
of it.

31. Give the construction of the Davy safety lamp and
describe a laboratory experiment to illustrate the principle
on which its safety depends.

32. Describe the construction and explain the operation
of a Bunsen burner.

33. Compare the action of carbon and chlorine as disin-
fecting agents.

34. Give the theory to account for the formation of
(«) petroleum ; (6) natural gas.

35. Describe a method of preparing acetylene and state
its physical and chemical properties.

36. (") Explain the formation of marsh gas in nature.
(6) Distinguish between carbohydrate and hydrocarbon,
(c) Mention two groups of carbohydrates.

37. Describe the manufacture of glass and distinguish
between window glass and green bottle glass.

38 REVIEW QUESTIONS AND PROBLEMS

38. Mention («) the principal products obtained from the
destructive distillation of bituminous coal ; (b) two great
natural sources of C02. (c) Explain why the percentage of
C02 in the air remains nearly uniform.

39. Describe the preparation and give the properties and
uses of (a) lampblack ; (6) coke, (c) What is the source of
gas carbon and its use ?

40. If a candle consists of 87 per cent carbon and of
13 per cent hydrogen, what weights of C02 and of H20 will
be formed when 50 g. of the candle burn ?

41. What weight of CO will be formed upon treating
25 g. of oxalic acid with concentrated sulphuric acid ?

42. Name the natural and artificial forms of free carbon
and state how they differ from one another.

43. What volume of C02 would be formed respectively
by the complete combustion of (ft) 12 1. of acetylene ? (i) 7 1.
of propane (CJIJ ? (c) 75 cc. of CO? (d) 2.5 1. of methane?
(e) 4 1. of ethylene (C2H4) ?

44. Through what cycle does carbon pass in animal and
vegetable life ?

45. How may coke be converted into graphite ? What is
animal charcoal ? For what purpose is it used ?

46. Describe («) the process employed in the manufacture
of carborundum. Of what practical use is the substance ?
(i) In what forms does silica occur in nature ? In what
industry are silica and the silicates of great importance ?

47. Calculate the weight of calcium carbonate that could
be precipitated by the action of 10 1. of C02 (measured under
745 mm. pressure at 21° C.) upon a solution of Ca(OH)2.

48. Name three allotropic forms of carbon and show how
their chemical identity may be proved. By what reaction
may C02 be distinguished from CO ?

CARBON, SILICON, TIN, LEAD GROUP 39

49. What is allotropy and how is it illustrated and
accounted for in the case of the element carton ?

50. Name three important substances obtained by the
destructive distillation of (W) wood ; (/>) soft coal.

51. What is an alloy? Mention an alloy and state three
ways in which its properties differ from those of its constit-
uents. Name an alloy of lead and of tin.

52. Make a comparison between («) carbon and silicon as
to compounds formed ; (/») between carbon, oxygen, sulphur,
and phosphorus as to allotropic forms.

53. Suggest a probable way that natural gas has been
formed.

34. Coal frequently contains sulphide of iron. What
sulphur compounds are likely to be formed when gas is
made from such coal, and what would be the method for
the removal of these compounds ?

55. Could a solution of NaOH be substituted for the
solution of Ca(OH)2 in testing for CO2?

56. How would you distinguish between C02, and O, H,
N, and NaO ?

57. How would you distinguish between carbonates and
sulphites ?

58. Write the equations for the preparation of MgCO8,
BaCO8, KaC08, Na2CO8, and CaC08.

59. How would you detect the presence of lead in tinfoil?

60. Since stannous chloride reduces gold chloride, give
the equation for extracting gold.

61. What sulphates other than lead are insoluble ?

62. (o.) In what respect is silica similar to tin and lead ?
(b) Given one ton of cassiterite, how much tin could be
obtained by its reduction ?

40 REVIEW QUESTIONS AND PROBLEMS

63. How can you determine whether a given crystal is
quartz or calc-spar ?

64. Dumas, in 1859, added to a solution containing 4.5049
of stannous chloride an excess of a solution of silver nitrate
and found that the precipitate of silver chloride formed con-
tained 7.481 g. of silver. What is the atomic weight of tin,
if the atomic weights of Cl and Ag are 35.43 and 107.94
respectively ?

65. Explain the principle of the chemical fire extin-
guisher, state what materials are used, and give the
equation.

66. Give the most important use of silicon dioxide and
explain why silicon is not found free in nature.

67. What is water glass ? How is it produced and what
are its uses ?

68. Calculate the percentage of C02 and CO and restate
the percentages in a form which illustrates the Law of
Multiple Proportions.

69. A gaseous hydrocarbon contains 85.71 per cent of
carbon ; its density referred to oxygen is .875. What is its
simplest formula and its molecular formula ?

70. Write the formulas for the following compounds :
silicon iodide, hydrogen silicide, silicon sulphide, carbon
silicide.

71. Write the equations for the preparation of silicic acid ;
carbonic acid. Write the formulas of the following: k-ud
sodium acetate, stannous bromide, thorium nitrate, cerium
sulphate, lead chromate, lead sulphide, lead tetroxide, stannic
chloride, stannous sulphide, stannic oxide.

72. Thorium is much like what other newly discovered
element ?

73. How is animal charcoal obtained?

THE HALOGENS 41

74. Describe the manufacture of shot, touching on (a) sub-
stances used; (6) processes used. Explain each process
mentioned. Why is arsenic used in the manufacture of shot?

75. Give a laboratory method of preparing each of the
oxides of carbon. Compare the chemical properties of these
oxides and state the effects of each on animal life. Explain
the formation of each in a coal fire.

CHAPTER XIV
THE HALOGENS

1. How may chlorine, bromine, and iodine be prepared ?
Write the equation representing the reaction involved in
each case. Why are these elements grouped together?

2. Describe another method for the preparation of chlo-
rine and write the equation for the reaction involved.

3. Why is moisture necessary to the bleaching action of
Cl? What is formed when hydrogen burns in chlorine and
how may the product be distinguished from chlorine ?

4. («) How may chlorine be prepared ? State its prop-
erties. (£») What elements constitute the halogen group and
why are they grouped together ?

5. Give the properties of Cl and state what is formed
when it is passed into a hot concentrated solution of
potassium hydroxide.

6. What weight of chlorine will be set free when a so-
lution containing 75 g. of sodium chloride is electrolyzed,
and what will be the volume of the chlorine gas thus made
at a temperature of 20° C. and a pressure of 740 mm.?

7. How many liters of chlorine can be obtained from
. of common salt?

42 REVIEW QUESTIONS AND PROBLEMS

8. Name the principal characteristics of each of the
halogens in the free state. Why are they grouped together ?
Describe a method for the laboratory preparation of free
bromine and write the reaction.

9. What is the chief source of iodine in commerce ?
What are its properties ? How may its presence be detected ?

10. Calculate the approximate weights in grams of 1 1.
of each of the following gases : C12, HC1, HBr, HF.

11. What weight of chlorine can be prepared from 78 g.
of rock salt containing 99 per cent NaCl ? How much
manganese dioxide and sulphuric acid would be required to
carry out the reaction ? What volume would the chlorine
occupy under standard conditions ? What volume of hy-
drochloric acid would be formed ?

12. Write the equation for preparing hydrofluoric acid.
Describe and explain the process of etching glass. State two
methods of identifying iodine.

13. Describe and explain the action which occurs when
chlorine water is added to a solution of potassium iodide
containing starch.

14. If 100 g. of magnesium are completely dissolved in
hydrochloric acid, what volume will be occupied at 18°C.
and 760 mm. by the gas evolved ? If this gas is then burned
in oxygen, what substance will lie produced and how much ?

15. If a quantity of a gas measures 493 1. at 784 mm. and
20° C., what will be its volume under standard conditions ?
Supposing the gas to be hydrogen chloride, calculate its
weight. What weights of materials would be required to
prepare it ?

16. What occurs when Cl is passed into («) a cold and
dilute solution of potassium hydroxide, and (ft) into a hot
and concentrated solution ?

THE HALOGENS 43

17. Mention some important chlorides formed in nature ;
some that are artificially produced.

18. Describe in detail the process of bleaching, giving
the reaction involved.

19. What is chlorinization ? What are the tests for
chlorine and the chlorides ?

20. Give the reaction involved in the process of disin-
fecting with Cl.

21. Name the acids of Cl and write and name the zinc
salt of each.

22. Compare the elements of the halogen group as to
(a) state, (6) color, (c) weight, (d) chemical activity.

23. Calculate the volume of hydrochloric acid solution,
density 1.1 and 20 per cent pure acid by weight, that would
be required, to neutralize 50 g. of Ca(OH)2.

24. How may Cl and HC1 gas be obtained, starting from
common salt in each case ? In what chemical way may
these two substances be distinguished from each other ?

25. Give reasons why the halogens are regarded as
members of a natural group of elements.

26. How do you ascertain the properties of HC1 and how,
in addition, could you show that this compound contains
(a) hydrogen ? (6) chlorine ?

27. Describe the preparation of HC1 as a by-product in
the manufacture of sodium carbonate. Give its physical
and chemical properties.

28. Describe in detail an experiment illustrating the
bleaching properties of Cl.

29. Give the important physical and chemical properties
of iodine. Mention one source and two uses of iodine.

44 REVIEW QUESTIONS AND PROBLEMS

30. Write equations for the preparation of potassium
bromide by three different methods.

31. If a solution contains potassium bromide and potas-
sium chloride, how would you show the presence of the
halogens ?

32. How do you account for the fact that solutions of
hydriodic acid become dark on standing some time ?

33. Write the equations for the reactions of bromine with
zinc, water, antimony, and hydrogen.

34. How many liters of N may be obtained by the inter-
action of Cl with NH8?

35. If the weight of 1 1. of HC1 gas is 1.735 g., what is
the elemental weight of chlorine ?

36. How many grams of NaCl are required to prepare
half a kilogram of hydrogen chloride ?

37. The analysis of a certain compound gave the following
results :

1. C = 12.00 per cent 2. 11.69 per cent 3. 11.83 per cent

H = 3.98 per cent 4.02 per cent 4.00 per cent

N = 6.77 per cent 6.80 per cent 6.78 per cent

Br = 77.56 per cent 77.61 per cent 77.64 per cent

What was the formula ?

38. A saturated solution of Cl when exposed to sun-
light yielded 20 cc. of a gas. How would you establish
the identity of the gas and how much Cl was required to
produce it ?

39. CaO + 2 NH4C1 = 2 NH8 + H20 -f CaCl2. Given 56
grains of lime, how many cu. ft. of ammonia at 0° C. and
15 Ib. pressure would result from the above reaction ?

40. Write the formulas for the following compounds :
magnesium iodide, mercuric bromide, silicon fluoride, ferrous
bromide, ferric chloride, lead iodide.

THE ALKALINE-EARTH METALS 45

CHAPTER XV
THE ALKALINE-EARTH METALS

1. What reaction takes place when magnesium flash-
light powder is set on fire ?

2. The gas density of mercury is 100. What is the for-
mula for the molecule ? Why is nitric acid a better solvent
for Hg than hydrochloric ?

3. What is the approximate specific heat of cadmium,
accepting 112 as its atomic weight ?

4. How much Hg is formed by decomposing 500 g. of
cinnabar ?

5. Write the formulas for the following compounds :
mercuric sulphate, mercuric iodide, mercurous bromide, cad-
mium sulphate, cadmium iodide, zinc iodide, zinc acetate,
potassium zincate, magnesium fluoride, magnesium phos-
phate, ammonium magnesium phosphate, magnesium iodide.

6. What properties have the metals of the magnesium
family in common with the alkali metals ? with the alkaline-
earth metals ?

7. Distinguish between magnesium chloride and magne-
sium sulphate ; between Epsom salts and Glauber salts.

8. What hydroxide studied, other than zinc hydroxide,
has both acid and basic properties ?

9. What property of Mg is made use of in the isolation
of argon ?

10. Erdman and Marchand, in 1844, obtained 352.4079 g.
of mercury by heating 380.5744 g. of mercuric oxide. What
is the atomic weight of mercury ?

11. How may quicklime be prepared? What chemical
change takes place in the drying of ordinary mortar ?

46 REVIEW QUESTIONS AND PROBLEMS

What substances ordinarily cause temporary and perma-
nent hardness in water ? Write the equation representing
the reaction involved in the removal of temporary hardness
by boiling.

12. Name four forms in which calcium carbonate occurs
in nature. How may quicklime be prepared ? What happens
when water is added to quicklime ? What is plaster of
Paris and from what is it made?

13. What is meant by radioactivity ? What is the pres-
ent source of radium ? What are the effects of the rays
given off from radium ?

14. Explain in detail how such elements as sodium and
calcium can be detected with the aid of the spectroscope.

15. The most important ore containing mercury is cin-
nabar (HgS). Where is it found ? How is the mercury
extracted from it ? What are the commercial names of
inercurous chloride and mercuric chloride and how do the
two differ from each other in chemical properties ?

16. 'xiow many grams of quicklime and how many liters
of C02 would be formed by heating 1 kg. of limestone ?

17. What substances ordinarily cause temporary and
permanent hardness of water respectively ? Explain the
chemistry involved in the removal of temporary hardness
and give the equation expressing the reaction.

18. What weight of Zn would be required for the pro-
duction of sufficient hydrogen, at 21° C. and 745 mm. pressure,
to fill a balloon having a capacity of 100 cc. ?

19. What weight of calcium carbonate is required to neu-
tralize 400 cc. of hydrochloric acid solution which contains
100 g. of the pure substance ?

20. A flask has a capacity of 15 1. The prevailing temper-
ature is 18° C. and the atmospheric pressure is 752mm.;

THE ALKALINE-EARTH METALS 47

what weight of Zn, reacting with H2S04, would be needed to
fill the flask with hydrogen under the prevailing conditions ?

21. How is lime prepared? What is the action of the
atmosphere upon it ? What is mortar ? How is it prepared
and what chemical changes occur when it hardens ?

22. What is the specific heat of cadmium if its atomic
weight is 112 ?

23. How much («) calomel can be obtained from 200 g. of
mercurous sulphate ? (£>) how much corrosive sublimate ?

24. Hauer, in 1868, found by heating 64.2051 g. of cad-
mium sulphate (CdS04) that 44.4491 g. of cadmium sulphide
were left. Taking the atomic weights of oxygen and sulphur
as 16.00 and 32.06 respectively, calculate the atomic weight
of cadmium.

25. Why is normal calcium phosphate converted into
superphosphate in the manufacture of fertilizers ?

26. How is a limekiln built, and why is the production of
lime hastened by blowing air or steam into the kiln ?

27. What is the test for a magnesium compounu ? for
zinc ? for strontium ? for cadmium ?

28. Name two alloys of zinc and state what each contains.

29. How is zinc obtained from its ores ? Mention two
ways to prepare zinc sulphide.

30. Name a compound of Zn used as a base for paint. Why
is a zinc paint especially valuable in chemical laboratories ?

31. What special name is given to the alloys of mercury ?

32. How would you test for a soluble salt of Hg ? Calcu-
late the percentage composition of the two chlorides of Hg.

33. Give a method for making zinc chloride from the
sulphate, with equations. Write equations for the reactions
of a dilute solution of («) zinc bromide, with silver nitrate ;
(/>) sodium hydroxide ; (c) chlorine ; (it) ammonium sulphide.

48 REVIEW QUESTIONS AND PROBLEMS

34. Write equations showing four methods by which the
salt, zinc sulphate, could be made.

35. Describe the process of converting (a) limestone into
quicklime ; (6) quicklime into slaked lime. Write the re-
action .in each case.

36. Mention three ores of zinc. Describe the ordinary
method of extracting zinc from the ores mentioned. Write
the reaction.

37. Give the physical and chemical properties of Zn and
describe the process of galvanizing and explain its use.

38. Show by equation how the following compounds of
zinc may be obtained from metallic zinc : the oxide, chloride,
nitrate, carbonate, sulphate, sulphide, hydroxide.

39. Write the equation for the reaction between barium
chloride and sulphuric acid in (a) the ordinary chemical
form and (6) the ionic form.

40. If 64.2508 g. of cadmium sulphate yield 44.4491 g. of
cadmium sulphide, what is the atomic weight of cadmium ?

41. How is Zn obtained in a commercial scale from zinc
ore ? Why is it used for galvanizing iron wire ? What com-
pound of Zn is used in the manufacture of paint? Define
the terms "alloy" and "amalgam" and give an example
of each.

42. What is meant by radioactivity ? What are alpha,
and beta particles? Are they electrons? Does radioactivity
differ from other chemical reactions ?

43. Describe, writing the equations to express the reac-
tions in each case, the chemical changes that take place in
the calcium compound from the time it leaves the quarry as
limestone till it hardens into plaster on the wall.

44. Calculate the simplest formula for a compound having
the percentage compositions Ca = 40, C = 12, O = 48.

THE ALKALI METALS 49

CHAPTER XVI
THE ALKALI METALS

1. Write the formulas of the following compounds by
applying the principles of valence : sodium fluoride, sodium
phosphate, sodium chlorite, sodium acetate, potassium man-
ganate, acid potassium sulphite, lithium carbonate, lithium
chloride, lithium phosphate, potassium nitrate, sodium sul-
phate.

2. How much sodium will 4 kg. of sodium carbonate
yield if heated with carbon ?

3. Describe the preparation of potassium hydroxide from
potassium carbonate and write the reaction. Give the phys-
ical and chemical properties of potassium hydroxide.

4. Describe the Solway process of manufacturing sodium
carbonate. Write the reactions.

5. (a) Mention two alkali metals and give the formulas
for their hydroxides, carbonates, and sulphates ; (b) point
out how these compounds differ in solubility from the cor-
responding compounds of the alkali-earth metals.

6. What is formed when a solution of sodium hydroxide
is saturated with hydrogen sulphide ?

7. Give a brief description of making soda from common
salt and making caustic soda from soda.

8. Describe the manufacture of caustic soda from rock
salt according to the electrolytic process.

9. Describe the Le Blanc process of manufacturing
Na2S04.

10. Give a complete description of the action of the metal
sodium upon water. Give the properties of the products of
the action. Give a similar account of potassium.

50 REVIEW QUESTIONS AND PROBLEMS

11. How many grams of sodium will be needed to com-
bine exactly with a quantity of chlorine which at 18° C. and
740 mm. occupied a volume of 200 cc. ? What will be the
weight of the resulting salt?

12. Describe the commercial electrolytic method of ob-
taining the metal sodium and write the reaction.

13. Write the equations for the

1. Action of dilute sodium hydroxide on chlorine.

2. Nitric acid neutralized by potassium hydroxide.

14. Name the potassium salt and give the formula for
each of these acids: HC1, HC10, HC102, HC103, HC104,
HN02, HN08, H2S04, HBr, HgAsO4, HF.

15. What weight of NaOH must be dissolved in 1 1.
of water to yield a solution of such strength that 10 cc. of
it will exactly neutralize 5 cc. of a solution of HNOg that
contains 126 g. of the acid in 11.?

16. Describe in detail what happens when a solution of
sodium sulphate is electrolyzed. How may the direction
of the current be determined ?

17. How many kilograms of crystallized sodium carbonate
(Na2C08 • 10 H20) could be obtained from 1000 kg. of salt ?

18. What weight of HNOg would be required to exactly
neutralize 30 g. of NaOH, and what weight of sodium nitrate
would be formed ?

19. Write the equations

1. Potassium and sulphuric acid.

2. Calcium hydroxide and ammonium hydroxide.

3. Sodium hydroxide and phosphoric acid.

4. Ferric chloride and ammonium hydroxide.

20. Give the formulas for three important compounds of
sodium. How are these compounds obtained and to what
use are they put ?

THE ALKALI METALS 51

21. Write the formulas for the following compounds and
name the acids of which they are salts: sodium hypochlo-
rite, sodium chlorite, sodium chlorate, sodium perchlorate,
sodium chloride.

22. What is water glass ? Give two uses to which the
substances may be put.

23. How many grams of potassium hydroxide are con-
tained in 11. of a solution that 6.4 cc. will completely
neutralize 9.6 cc. of normal solution of HC1 ?

24. How much sodic chloride may be obtained from 10 g.
of crystallized sodic carbonate ?

25. To what extent does the composition of a pure chem-
ical compound vary ? Take as an example pure 'sodium
chloride from various sources and mention other examples
if possible.

26. Discuss the use of potassium compounds as a fertilizer.
State the co'mmon form and its formula.

27. Name two compounds of sodium which are commonly
employed in the household and give the use of each.

28. What are constituents of common gunpowder ? What
is the formula for caustic potash ?

29. How may Na2COg • 10 H20 be converted into NaOH,
and how may metallic sodium be made from NaOH ? Give
reactions.

30. Give the tests for sodium ; for potassium ; for lithium.

31. Explain the formation of potassium nitrate by
nitrification.

32. In what location are sodium, potassium, and lithium
produced in nature ?

33. Give the chemical difference between sodium carbon-
ate and sodium bicarbonate. What are their common names
and their uses ?

52 REVIEW QUESTIONS AND PROBLEMS

34. If a gram of gunpowder produces 300 cc. of gas at
O° C., what will its volume be at 2000° C. ?

35. Give the important compounds of lithium ; their
properties and uses. Give the properties of lithium.

36. Name all the members of this group and compare
them as to common characteristics.

37. Which of these gases would you dry with solid caustic
potash : oxygen, carbon dioxide, ammonia, carbon monoxide ?

38. How would you prove the presence of potassium in
plants ?

39. Distinguish by analysis between sodium chloride and
ammonium chloride.

40. How would you distinguish between KF, KI, Kl>r,
KC1?

41. Why does KHS04 react acidic, while NaHCO8 reacts
alkaline ?

42. Sodium nitrate is used in the preparation of H]^()3.
Why not potassium nitrate ?

43. How could you prove that the water in crystals of
NaCl is not water of crystallization ?

CHAPTER XVII
ALUMINUM-BORON GROUP

1. How is aluminum obtained ? Is the method of elec-
trolysis used in decomposing the more stable or the less
stable compounds ?

2. What care must be taken of kitchen utensils made of
aluminum ?

3. (a) How could you prove that alum contains alumi-
num ? (U) What are the properties of aluminum ?

ALUMINUM-BORON GROUP 53

4. Explain why alum turns litmus red and borax turns
litmus blue.

5. What is the per cent of aluminum in (a) cryolite
(Na8AlF6)? (ft) in turquoise (Al^O, • H8A1206 • 2 H2O)?

6. Write the formulas for aluminum sulphide, aluminum
phosphate, aluminum acetate, potassium aluminate.

7. Write the equation to show how aluminum hydroxide
can play the part of a base ; of an acid.

8. What compound of aluminum is formed when a solu-
tion of calcium carbonate reacts with a solution of aluminum
sulphate ?

9. Describe briefly the commercial process for the prepa-
ration of aluminum from aluminum oxide.

10. Give the properties of metallic aluminum and the
name and formula of an important salt.

11. How many grams of aluminum can be obtained from
200 kg. of bauxite (A1208 - 2 H20) ?

12. Describe the reaction that takes place between metallic
aluminum and ferric oxide when a mixture is ignited. Give
the equation and state what practical applications are made
of the reaction.

13. Describe in detail the Goldschmidt process for weld-
ing iron, giving the equation expressing the reaction.

14. («) Complete and balance the following:

1. Ala(S04)8 + KOH= 3. A1(OH)8 + HC1 =

2. Al (OH), + KOH = 4. AgN08 + KBr =

(i) Is aluminum hydroxide to be regarded as an acid or
as a base?

15. What is the composition of the mixture termed
" thermit " ? What is the chemical action that takes place
between these components ? What practical use is made of
thermit ?

54 REVIEW QUESTIONS AND PROBLEMS

16. Explain the use of aluminum sulphate in the purifi-
cation of water.

17. Having solutions of magnesium sulphate, cadmium
chloride, and aluminum sulphate, how would you test for
the metallic ions ? What is a mordant ?

18. What are the products obtained by heating sodium
sulphate with boracic acid?

19. How many grams of C02 are evolved when 200 g. of
borax are made by the interaction of boric acid and Na2CO3 ?

20. Which contains the larger percentage of boron — boric
acid, boracic acid/ or boron trioxide ?

21. What is the formula for ferric ammonium alum and
what are its properties and uses ?

22. Terreil, in 1879, found that 0.0455 g. of H was
evolved when 0.410 g. of aluminum was dissolved in an
acid. What is the atomic weight of aluminum calculated
from this experiment ?

23. What hydroxides other than aluminum hydroxide
have both acid and basic properties ?

24. Write the equations for the preparation of aluminum
hydroxide and aluminum sulphate.

25. Write the general formula of an alum, letting M
represent the atom of the alkali metal and X the atom of
the trivalent metal.

26. In what respect does aluminum oxide differ from cal-
cium oxide in properties ?

27. Explain the use of borax for the " softening of water" ;
the use of it in the " borax bead's " test.

28. How could Al, NH4, and S04 be recognized in an alum
solution ? Illustrate with equations.

29. What volume of 0 at 15° C. and 760 mm. is needed to
change 8 Ib. of aluminum into aluminum oxide (A12O8) ?

IRON, NICKEL, COBALT, PLATINUM GROUP 55

CHAPTER XVIII
IRON, NICKEL, COBALT, PLATINUM GROUP

1. Does iron occur free in nature ? Give the reason.

2. Name and compare the three varieties of iron. Why
should these not be regarded as allotropic forms ?

3. There are two metallurgical processes. Iron illustrates
one and sodium the other. Describe each process.

4. Describe the manufacture of iron in the blast furnace.

5. Describe in detail the manufacture of pig iron from
iron ore.

6. Give the tests for iron.

7. Name at least three iron ores. Describe the manu-
facture of cast iron. What is the flux generally used in
smelting iron ? Name the chief chemical changes that take
place in a blast furnace. How is cast iron converted into
wrought iron and steel ?

8. How is steel made from pig iron by the Bessemer
process ?

9. Name an ore of each of the following metals : iron,
lead, zinc, and mercury. Give a test for a metal in each of
the following ways : (a) by flame coloration ; (£) by the
borax bead ; (e) by the blowpipe in charcoal.

10. How may a ferrous salt be prepared? a ferric salt?
Give a special test for each.

11. Name the ingredients of the furnace charge that
would be employed in the manufacture of cast iron from an
ore containing ferric oxide mixed with sand. Make a dia-
gram of the furnace.

12. What weight of 0 is required to unite with 21 g. of
iron to give the magnetic oxide of iron (Feg04)? What
volume will this 0 occupy at 10° C. and 750 mm. ?

56 REVIEW QUESTIONS AND PROBLEMS

13. Give the names of the different processes for produc-
ing steel from cast iron, and define ore and flux. Give
formulas for six important compounds of iron.

14. How would you (a) make ferrous chloride from iron ?
(6) ferrous sulphide from ferrous chloride ? (c) ferrous sul-
phate from ferrous sulphide ? (d) ferric hydroxide from
ferrous sulphate ?

15. In the above question write the equations for the re-
actions after giving the descriptions of the processes, and
indicate the color of the product in each case.

16. How can ferrous sulphate be made from iron and this
compound converted into a ferric salt ? How would you test
for ferric oxide in the solution ?

17. Both iron and aluminum become oxidized upon ex-
posure to the air. Why does iron gradually disintegrate,
and why does aluminum remain not perceptibly changed ?

18. Why is iron pyrites an objectionable ore from which
to obtain iron ?

19. Russell, in 1869, found that the hydrogen produced
by the action of HC1 upon cobalt was 3.4917 per cent of
the metal. Calculate the atomic weight of cobalt.

20. Write the formulas for the following compounds :
potassium ferrocyanide, potassium ferricyanide, ferric ferro-
cyanide, ferrous ferricyanide, potassium cobalt nitrite, ferric
acetate, ferric nitrate, ferrous bromide, nickelic sulphate,
cobaltic nitrate.

21. Write the chemical and ionic equations for the displace-
ment of copper by iron in solutions of copper compounds.

22. What is a slag? How is it produced and what is
its use?

23. What is the method of preparation of platinum, and
what metal is likely to be alloyed with it ?

COPPER, SILVER, AND GOLD GROUP 57

24. When a solution of sodium carbonate is added to a
solution of a ferric salt, an hydroxide is precipitated and
not a carbonate. How is this explained ?

25. Give the tests for nickel and cobalt.

26. What is the only important compound of platinum,
and what is the use of platinum in the contact process in
the manufacture of H2S04?

27. Distinguish between chrome iron, nickel steel, spiegel
iron, and vanadium steel.

28. What is the minimum weight of carbon per ton of
steel that can be added and yet have the steel take a
temper ?

29. Describe the open-hearth process ; the Siemens-Martin
process of manufacturing steel.

30. State the most important uses of cobalt, its properties,
and how and when found.

31. Give the chemical and the common name of FeS.
How can it be prepared in the laboratory ? Give equation.

CHAPTER XIX
COPPER, SILVER, AND GOLD GROUP

1. Compare copper, silver, and gold in their physical
and chemical properties.

2. What is oxidized silver, German silver, sterling silver?

3. Write the formulas for the following compounds :
cuprous nitrate, cupro'us sulphide, cuprous iodide, cupric
acetate, silver cyanide, silver sulphate, silver oxide, aurous
bromide, auric chloride, aurous hydroxide, cupric hydroxide.

4. If 500 g. of silver interact with nitric acid, how much
silver nitrate is formed?

58 REVIEW QUESTIONS AND PROBLEMS

5. Write the equation for the reduction of cupric oxide
by hydrogen with heat.

6. What acid would you use to dissolve silver ? What
chemical test would show the difference between a solution
containing a silver salt and one containing a zinc salt ?
Write equations to illustrate both answers.

7. Write equations for the reaction between silver and
nitric acid ; also for the resulting solution with hydrochloric
acid. Describe the visible changes accompanying these
reactions.

8. Describe a process of obtaining copper from one of
its ores. Mention (</) the properties of copper, and (6) the
important uses.

9. Write the equation for the reaction of H2SO4 on
copper when heated. Explain why the gaseous product
obtained differs from that usually produced by the action
of an acid on a metal.

10. Define cupellation. Describe a process of extracting
silver from its ores by cupellation.

11. Calculate the percentage of water of crystallization
in crystalline copper sulphate (CuS04 • 5 H2O).

12. An experiment showed that when 2.16 g. of silver
were treated with chlorine 2.87 g. of silver chloride were
formed. Calculate from this result the atomic weight of
silver.

13. Describe experiments by which you could determine
. whether or not an alloy contained silver.

14. Name the elements that enter into the composition
of the following alloys, and give the usual percentage rela-
tion : («) aluminum bronze ; (/>) brass ; (c) bronze ; (d) Ger-
man silver ; (e) gold coin ; (/) gun metal ; (</) nickel coin ;

A silver coin.

COPPER, SILVER, AND GOLD GROUP 59

15. How could you prepare pure silver chloride from a
silver coin ?

16. Account for the action of sulphur water and eggs
upon silver.

17. Silver may be cleaned by boiling it in water in an
aluminum vessel. Write .the equation for the action involved.

18. Silver nitrate and mercuric nitrate are both white salts
soluble in water. How could you distinguish between them ?

19. Describe, giving chemical reactions involved, the
amalgamated process of refining silver. Why is the silver
sulphide first changed into silver chloride ?

20. Why is silver not used as an electric conductor ?

21. Describe what takes place when a solution of silver
nitrate is electrolyzed (a) with both terminals of platinum ;
(A) with both terminals of silver.

22. What occurs when a solution of copper sulphate is
electrolyzed (a) with both electrodes of copper ? (b) with
both electrodes of platinum ?

23. («.) Describe the electrolytic purification of copper;
(fi) the method of electrolytic copperplating.

24. What chemical compound is ordinarily employed in
photography ? Describe briefly the chemistry of the different
steps taken in making a photograph.

25. Draw carefully a diagram of an apparatus for passing
H over red-hot oxide of copper. Include the details for mak-
ing the hydrogen gas and the arrangement for preserving
separately the products of the reaction.

26. State two ways by which an aqueous solution of a
copper salt may be distinguished from one of a ferric salt.

27. Why is plated ware softer than sterling silver? What
compound is usually formed when silver tarnishes ? Mention
two articles of food that cause silver to tarnish.

60 REVIEW QUESTIONS AND PROBLEMS

28. How does copper occur in nature ? What is blue
vitriol ? Give three tests for copper.

29. If 4.393 g. of copper precipitate 14.91 g. of silver
from a silver nitrate solution, and the atomic weight of
silver is 108, what is the atomic weight of copper ?

30. How would you account for the fact that solutions of
the different salts of a metal usually have the same color ?

31. How would you test for the presence of silver in
an ore?

32. From 10 cc. of a solution of silver nitrate 0.9365 g.
of silver chloride were obtained by precipitation with hydro-
chloric acid. How many grams of silver nitrate are contained
in a liter of the solution ?

33. Describe the chlorination and the cyanide processes
for extracting gold.

CHAPTER XX
CHROMIUM AND MANGANESE GROUP

1. Name the members of the chromium group.

2. Distinguish between trivalent and hexavalent
chromium.

3. Name the most important compounds of chromium.

4. Give the equation for the action of H2SO4 upon
potassium chromate, showing all steps.

5. How is permanganate solution used as a test for
organic matter in water ?

6. Name (a) the most important compounds of man-
ganese ; (7>) state their uses ; (e) give their characteristics.

7. In the preparation of 0 from KC10g manganese
dioxide is used. Explain its action and name the process.

CHROMIUM AND MANGANESE GROUP 61

8. How may potassium dichromate be converted into
potassium chromate and vice versa?

9. What is chrome iron, and what is the purpose in
using chromium in iron ?

10. Give the tests for Mn and for chromium.

11. Write the equations for the following reactions:

1.' Preparation of manganous chloride.

2. Preparation of manganous hydroxide.

3. Ferrous sulphate + potassium permanganate =

4. Ammonium sulphate -f- chromium sulphate =

5. Potassium chromate + hydrochloric acid =

12. How many grams of lead chromate can be made from
500 g. of potassium dichromate ?

13. Why is chrome alum called a double salt? What is
the meaning ?

14. How is manganese classified in the groups of the
elements ?

15. Describe the use of manganese in the manufacture of
Cl by the Welden process, and give the reactions.

16. What is known of molybdenum, tungsten, and
uranium ?

17. What is meant by the term " catalysis " ? Give a
reaction in which a catalytic agent is used.

18. What evidence is there from the study of chro-
mium and its compounds that oxygen is correctly called
acid former ?

19. How does K2Cr207 prevent the "polarization" of a
voltaic cell ? What chromium compound is formed in the
" dichromate " battery ?

20. Exactly 20 cc. of a solution containing 15.8 g. of
KMnO4 per liter were needed to react completely with a
solution of H./Xr How much H202 was there ?

62 REVIEW QUESTIONS AND PROBLEMS

CHAPTER XXI
ORGANIC ACIDS AND COMPOUNDS

1. What are hydrocarbons and where are they found in
nature ? Name some hydrocarbons which occur in illumi-
nating gas, and show how you would prepare any one of
them. Give the equations.

2. What volume' of ordinary air would be required for
the complete combustion of 15 1. of methane, and what
weight of C02 would be formed ?

3. State two physical properties of acetylene. Why does
it give out light when burned in the air ? Explain the
structure and principle of the acetylene burner designed to
prevent the gas from burning with a smoky flame. What
two products of combustion are formed when the gas burns
in air ? How may the presence of each be detected ?

4. What is the essential character of the common animal
fats ? Explain the process of soap making. What is the
difference between " hard " and " soft " soaps ?

5. Determine the molecular formula for a compound made
up as follows : carbon 80 per cent ; hydrogen 20 per cent ;
vapor density 15.

6. The formula for ethane is C2H6. Calculate the specific
gravity of its vapor (a) compared with hydrogen ; (6) com-
pared with air.

7. Find the proportions by weight and by volume in
which ethane gas (C2Hg) will combine with oxygen.

8. What is a soap ? Name two soaps soluble in water ; one
not soluble in water. Describe a process for making soap.

9. Mention (a) four hydrocarbons ; (i) four carbohydrates.
Write the formula of each compound mentioned.

ORGANIC ACIDS AND COMPOUNDS 63

10. Describe an experiment to show the presence of each
of the following in kerosene oil : («) carbon ; (/>) hydrogen.

11. Mention three organic acids. State the physical and
chemical properties of each.

12. Find the weight of each of the products of combus-
tion of 52 g. of camphene (CJOH16).

13. Describe a method of preparing sulphuric (common)
ether, and mention its properties and uses.

14. Describe the changes that take place when grape
juice undergoes («) alcoholic fermentation; (/<•) acetic fer-
mentation, and write the reaction in each case.

15. Write the graphic formula for marsh gas and find its
percentage composition.

16. Compare common (ethyl) alcohol with wood spirit
(methyl) alcohol as to («) sources ; (6) important properties
and uses.

17. Name the three classes of carbohydrates and write
the chemical formula for each.

18. How would you bring about the alcoholic fermenta-
tion of grape sugar ? Write the equation. Give a test for
each of the products of the fermentation.

19. Write the chemical formulas for the following com-
pounds : iodoform, wood alcohol, formaldehyde, ether, acetic
acid, starch, chloroform.

20. Describe cane sugar and acetic acid, touching on
(a) production ; (/>) physical properties ; (c) chemical prop-
erties ; ((F) chemical formula.

21. Describe the manufacture of wood alcohol, and state
its properties and uses.

22. Explain the instability of organic substances and
state its importance in (</.) nature; (b) fuels.

64 REVIEW QUESTIONS AND PROBLEMS

23. State the eight divisions of organic compounds, and
give the important members of each.

24. Compare isomerism and allotropy, and give examples
of each.

25. What is saponification, and how is it illustrated ?

26. Explain how collodion is related to cellulose.

27. Explain the relation of methyl chloride to wood
alcohol. How is methyl chloride used in surgery ?

28. Write the equation expressing the reaction that takes
place when formaldehyde is prepared from wood alcohol.
State the relation between formaldehyde and formalin.

CHAPTER XXII
EQUATIONS AND GENERAL FORMULAS

1. Give the formulas for borax, lime, quartz, green vitriol,
caustic soda, carborundum, marble, plaster of Paris, pyrite,
and cinnabar.

2. Give the name, formula, method of preparation, and
use of each of two carbides extensively used.

3. Classify as acids, bases, or salts, and give name of
each: NaOH, HF, NaOCl, KC108, NaHC08, NH4N03,
NH4OH, K2S04, Ca(OH)2, HN02.

4. Complete the following equations, using formulas :

1. Barium chloride + sodium sulphate =

2. Hydrogen sulphide + bismuth chloride =

3. Ammonium chloride + calcium oxide —

4. Sulphur dioxide + chlorine + water =

5. Give the name and formula of a binary compound, an
acid containing oxygen, a base, and a normal salt.

EQUATIONS AND GENERAL FORMULAS 65

6. Give the chemical name of each of the following sulv
stances : calomel, brimstone, fire damp, choke clamp, muriatic
acid, oil of vitriol, copperas.

7. Complete, using formulas :

1. Nitric acid -f sodium carbonate =

2. Ammonium chloride + caustic soda =

3. Water + metallic sodium =

4. Manganese dioxide + hydrochloric acid =

8. Give a chemical method of distinguishing between
each of the following:

1. Hydrogen and carbon monoxide.

2. Hydrogen chloride and sulphur dioxide.

3. Oxygen and nitrous oxide.

4. Nitrogen and carbon dioxide.

9. Classify these compounds under the headings (a) acids,
(&) bases, (c) normal salts, (d) acid salts, (e) anhydrides,
(/) oxides: CO2, NaHS04, CaCl2, PbO, H8P04, Ca(OH)2,
NaSO8, Mn02, S02, KC1, KHS04, NH4OC1, NaOH, CaF2,
HI, NH4OH, Ca(C10,)a, NaN08.

10. Complete the following equations, using symbols and
formulas :

1. Ammonium hydroxide + hydrochloric acid =

2. Ammonia + hydrochloric acid =

3. Sodium chloride + silver nitrate =

4. Ferrous sulphide + sulphuric acid =

5. Lead nitrate + hydrogen sulphide =

6. Manganese dioxide + hydrochloric acid =

7. Calcium carbide + water =

8. Arsenic trioxide -f nascent hydrogen =

9. Sodium carbonate + nitric acid =

10. Calcium hydroxide + carbon dioxide =

66 REVIEW QUESTIONS AND PROBLEMS

11. Complete and balance :

1. A12(S04)3 + KOH = 3. A1(OH)3 + HC1 =

2. Al (OH), + KOH = 4. AgN08 + KBr =

5. CaCO8 + C02 + H20 =

12. Give chemical names and molecular formulas for the
following : borax, Epsom salts, Glauber salts, white vitriol,
green vitriol, blue vitriol, iron pyrites, hematite, magnetite,
potash, galena, alum, gypsum, and cryolite.

13. Classify as acids, bases, or salts, and name : H2S04,
KC1, KHS04, NH4OC1, NaOH, CaF2, HI, NH4OH, Ca(C108)2,
NaN08.

14. For what do the following symbols and formulas stand :
S02, C, CH4, Fe08, CO2, CaCO3, Hg, I2, H3P04, NaOH, (OH),
(NH4), NH3, Ag, Al, 03, S., As/)., SnO2, and Pb(OH)2?

15. Complete and balance :

1. NaOH + H2S04 = 3. Na + HaO =

2. Mg + HC1 = 4. NaN03 + NH4C1 + II. E. =

5. NaCl + Mn()2 + H2S04 + H. E. =
NOTE. H. E. stands for heat energy.

16. Write the formulas for the following compounds and
name the acids of which they are salts : sodium hypochlorite,
sodium chlorite, sodium chlorate, sodium perchlorate, sodium
chloride.

17. Give the names of the following acids and of the
sodium salt of each: HC1, HC10, HC102, HC103, HC104,
HNO2, HN08, HBr, HI, HF.

18. Write the equations for the following reactions :

1. Silver nitrate and sodium chloride.

2. Aluminum sulphate and potassium hydroxide.

3. Ammonium chloride and slaked lime.

4. Sodium chloride, manganese dioxide, and sul-

phuric acid.

EQUATIONS AND GENERAL FORMULAS 67

5. Sodium hydroxide and sulphuric acid.

6. Chlorine and potassium bromide.

7. Steam and incandescent coke.

8. Calcium carbide and water.

9. Calcium hydroxide and carbon dioxide.
10. Methane and oxygen (ignited).

19. Write the equations for the reactions between the
following substances :

1. Calcium carbonate and hydrochloric acid.

2. Potassium nitrate and sulphuric acid.

3. Copper and water vapor (heated).

4. Aluminum sulphate ancPammoiiiuiu hydroxide.

5. Calcium carbide and water.

20. Write the formulas for the following :

1. Potassium chloride. 6. Ferrous sulphide.

2. Sodium carbonate. 7. Ferric chloride.

3. Phosphoric acid. 8. Aluminum sulphate.

4. Sodium cyanide. 9. Cuprous oxide.

5. Ferric oxide. 10. Manganese dioxide.

21. Write the equations for the following reactions:

1. Potassium hydroxide and sulphuric acid.

2. Calcium hydroxide and sulphuric acid.

3. Calcium hydroxide and ammonium sulphate.

4. Ferric chloride and ammonium hydroxide.

5. Sodium hydroxide and phosphoric acid.

6. Ammonium nitrate and heat.

22. Write the formulas for

1. Sodium carbonate. 4. Arsine.

2. Lead sulphate. 5. Arsenic trioxide.

3. Silica. 6. Ammonium sulphide.

7. ^Normal c;ilcium phosphate.

68 REVIEW QUESTIONS AND PROBLEMS

23. Write the formulas for

1. Limestone. 5. Aluminum phosphate.

2. Secondary sodium phos- 6. Mercurous chloride.

phate. 7. Barium nitrate.

3. Cupric sulphate. 8. Acetylene.

4. Ammonia. 9. Gypsum.

10. Marsh gas.

24. Classify as acids, bases, or salts: NaN08, NH4C1,
HC10, NH4OH, BaS04, Ca(NO8)2, HC104, Sr(OH)2, HN02,
Fe(OH)8.

25. Write the formulas for

1. Barium perchlorate. 6. Sodium perchlorate.

2. Ammonium sulphate. 7. Calcium hypochlorite.

3. Strontium nitrate. 8. Barium hydroxide.

4. Calcium sulphate. 9. Strontium oxide.

5. Ferric sulphate. 10. Barium nitrate.

26. Complete and balance :

1. CaC03 + HC1 = 6. Mn02 + NaC 1 + H2S04 =

2. Mn02 + HCl= 7. Zn + H2S04 =

3. A12(S04)8 + NH4OH = 8. CaC2 + H20 =

4. CuS04 + H2S = 9. H20 + C (hot) =

5. KOH + H8P04 = 10. Cl + KOH =

11. FeCl8 + NH4OH =

27. Give the structural formulas of NH4C1, NH4OH, and
(NH4)2S04.

28. Complete and balance :

1. Na2C08 + HC1 = 6. Ca,(P04)2 + H2S04 =

2. CaC08 + HN08 = 7. NaOH + H3P04 =

3. A12(S04)8 + KOH = 8. KN08 + H2SO4 =

4. Zn + H2S04= 9. Mn02 + HC1 =

5. CuS04 + H2S= 10. SCyNCyOH + H20 =

EQUATIONS AND GENERAL FORMULAS 69

29. Write the formulas for

1. Marble. 6. Ammonium phosphate.

2. Primary sodium sulphate. 7. Ammonia.

3. Aluminum sulphate. 8. Silver nitrate.

4. Cuprous chloride. 9. Mercuric chloride.

5. Cupric oxide. 10. Quicklime.

30. Name the following: (NH4)2C08, NH4HOOg, NH4CN,
NH4H2P04, Au20g, Ba(C2H802)2, BaCr04, BiBrs, BiON08,
CsCl, NiAs, Os04, K2A12O4, K2PtCl4, FeAs04-2H20.

31. Name the following: NiS2, NaHC08, NaAuCl4 • 2 H2O,
SeCl2, RuCl2, CaAlSi2O8, SnF2, SrC2, TaBrfi.

32. Name the following: NaC104, HC1O, NO, KC1O2,
KN02, C.N,, H2S04, H2S8O4, H8PO4, HNaC08, Ca(OCl),
FeCl8, CuBr, HKC08, NH4C1, Ca(OH)2, H202, H8P08, C2H2.

33. Complete the following reactions, using formulas :

1. Iron + sulphuric acid =

2. Zinc oxide + nitric acid =

3. Calcium hydroxide + carbon dioxide =

4. Marsh gas + oxygen (ignited) =

5. Hydrogen sulphide + lead nitrate =

34. Classify into acids, bases, salts, or anhydrides : S08,
NaN08, HBr, Ba(OH)3, CaS04, P2O5, H8BO3, NH4OH,
H8P04, C02.

35. Complete, using formulas :

1. Ferrous sulphate -f hydrochloric acid =

2. Calcium carbonate -f- nitric acid =

3. Sulphurous acid + sodium hydroxide =

4. Silver nitrate + potassium bromide =

5. Ferric oxide + hydrogen =

6. Phosphorus pentoxide + water =

70 REVIEW QUESTIONS AND PROBLEMS

36. Write the equations for the preparation of :

1. Carbon dioxide from calcium carbonate.

2. Ammonium hydroxide from ammonium chloride.

3. Chlorine from hydrochloric acid.

4. Calcium hydroxide from calcium carbonate.

5. Nitric acid from sodium nitrate.

37. Complete, using formulas :

1. Sodium hydroxide + carbon dioxide =

2. Lead nitrate + hydrogen sulphide =

3. Calcium hydroxide + nitric acid =

4. Phosphorus + oxygen =

5. Sodium carbonate + calcium chloride =

6. Hydrogen + (hot) copper oxide =

State which of the above compounds are acids, bases,
salts, or anhydrides.

38. Write the equations for the preparation of («) sulphur
dioxide ; (6) hydrogen sulphide ; (V) ammonia ; ((f) carbon
dioxide; (e) nitric acid.

39. Give the chemical formulas for the following : dia-
mond, carborundum, black lead, marble, sand (pure), washing
soda, lye, blue vitriol.

40. State which of the reactions indicated below will take
place in aqueous solution, and which will not, and give
the reasons for your conclusion in each case. Complete the
equations, using formulas :

1. Barium chloride + silver nitrate =

2. Calcium chloride + carbon dioxide + water =

3. Copper sulphate + zinc =

4. Ferrous sulphate -f- copper =

5. Calcium hydroxide + nitric acid =

41. Name two metals which have a valence of 2 and 3
respectively, and write the formulas for the nitrates and
sulphates of these metals.

EQUATIONS AND GENERAL FORMULAS 71

42. Give the chemical names and formulas for the follow-
ing: baking soda, brimstone, slaked lime, litharge, quick-
silver, oil of vitriol, sal ammoniac, alum, plaster of Paris,
quartz, niter.

43. Write the molecular formulas for ozone, sodium sul-
phate, carbon monoxide, aluminum chloride, potassium
hydroxide, calcium carbonate, ferric oxide, phosphorus
pentoxide, lead iodide, phosphoric acid.

44. Give the names of the following formulas : Hg (NOg)2,
CuO, Ag2S04, H202, Br2, Au, H2S, Pb(OH)2, BaC08.

45. Write the formulas for nitrogen peroxide, carbon
monoxide, sulphuric anhydride, calcium hydroxide, cupric
oxide, stannic chloride, hydrogen bromide, potassium car-
bonate, silver nitrate, lead sulphate.

46. Write a list of the formulas for the oxides of nitrogen,
and show how any of these can react with water. Point out
how any two of this series of compounds illustrate the Law
of Multiple Proportions.

47. Write equations showing laboratory methods of pre-
paring the following : (a) hydrochloric acid ; (i) sodium
carbonate ; (c) ferric hydroxide ; (cf) copper sulphate.

48. Give the chemical names and formulas for the follow-
ing: quicklime, marble, blue vitriol, bicarbonate of soda,
litharge, calomel. If any reactions are possible between
these substances and dilute sulphuric acid, write equations
tor show them.

49. Write equations for the preparation of («) CO2;
(l>) NaOH ; (c) H2S ; (d) AgCl ; (e) a basic oxide and HC1 ;
(/) an acidic oxide and KOH.

50. Describe the effects observed when chlorine water is
added (a) to mercurous chloride ; (It) to potassium iodide
solution. What inference do you draw about the reactions
that have taken place ?

72 REVIEW QUESTIONS AND PROBLEMS

51. Write the chemical names of the following: H2SO3,
NaHCO,, H2S, Fe2(SO4)8, P2O5, and show by equation how
each may be prepared.

52. Write the graphic formula for (a) nitric acid ; (b) cal-
cium carbonate ; (c) acetic acid.

53. Show by equation the bleaching action of (a) Cl ;

(*) so2.

54. Write the equations for the preparation of the follow-
ing acids other than by the direct combination of the elements
involved : H2S, HN08, H2S04, HBr, HC1, H2C08, H8P04.

55. Write the equations for the following reactions :

1. Potassium hydroxide and nitric acid.

2. Ferrous sulphide and hydrochloric acid.

3. Barium chloride and sodium sulphate.

4. Calpium hydroxide and ammonium chloride.

56. Write the chemical name of each of the following :
KHC08, AsH8, Ca8(P04)2, C6H1206, (C2H5)20.

57. Name and write the formulas for two oxides of
phosphorus and the acid corresponding to each.

58. Write the formula and give the chemical name of
saltpeter, laughing gas, sugar of lead, white vitriol, Glauber
salts, corrosive sublimate, plaster of Paris.

59. Describe minutely, giving chemical equations to show
the changes which take place :

1. When strong nitric acid reacts with metallic

copper.

2. When hydrogen sulphide is passed into a solution

of mercuric chloride.

3. When ammonium sulphate is heated with a solu-

tion of sodium hydroxide.

4. When bromine water and sulphurous acid are

mixed.

EQUATIONS AND GENERAL FORMULAS 73

60. («) Complete, using formulas :

1. Baric nitrate + potassic sulphate =

2. Ammonic chloride (solid) + calcic hydroxide

(solid) =

3. Sulphurous oxide •+- oxygen =

(fi) Give equations for making sulphuretted hydrogen.

61. Write the formulas for:

1. Three chlorides insoluble in water.

2. Four sulphates insoluble in water.

3. Two sulphides insoluble in water.

4. One carbonate soluble in water.

62. Name the following: NaCIO, NO, KN02, H2S08,
FeCl8, H8P04, HP08, CuaO, CuBr2, PbO2.

63. Write the equations for the chemical reactions below :

1. Ammonium chloride and slaked lime.

2. Manganese dioxide and hydrochloric acid.

3. Nitric acid and sodium hydroxide.

4. Sodium nitrate and sulphuric acid.

5. Manganese dioxide, sodium chloride, and sulphuric

acid.

64. Write equations for the following reactions :

1. Between lead peroxide and aqueous hydrochloric

acid.

2. On subliming mercuric sulphate and aqueous com-

mon salt.

3. Between aluminum sulphate and aqueous ammonia.

4. Between aluminum and potassium hydroxide.

5. Between copper sulphate and sodium hydroxide.

65. Write the formula for phosphoric acid, acetic acid,
hydriodic acid, chromic acid, silicic acid, sulphurous acid,
nitrous acid.

74 REVIEW QUESTIONS AND PROBLEMS .

CHAPTER XXIII

QUESTIONS AND CALCULATIONS

A. PERCENTAGE COMPOSITION

1. Find the percentage composition of carbon in («) CH4;
(ft) C2H2; (c) C2H4; (rZ) COS; («) C4H10; (/) C6H10O5.

2. Calculate the percentage composition of the follow-
ing compounds : carbon dioxide, ammonia, ferric oxide, ace-
tic acid, calcium sulphate, cream of tartar, ferrous sulphate,
alum.

3. How much sodium in (a) 10 g. of NaOH ? (ft) 19 g. of
Na2SO 4 ? (e) 15 g. of NaCl ? (d) 22 g. of NaHS04 ?

4. Calculate the percentage composition of (a) galena;
(7/) pitchblende.

5. How much anhydrous salt in («-) a kilogram of crys-
talline Glauber salts ? (b) alum ? (e) Epsom salts ? (//) sal
soda ? (e) copper sulphate ?

6. Find the percentage of the elements in a sample of
air which consists of 12.37 g. of N and 3.63 g. of O.

7. Calculate the percentage composition of (a) magnetic
oxide of iron (FegO4); (&) crystallized sodium carbonate
(Na2CCylOH20).

8. How many grams of argon can be obtained from
1500 kg. of normal air ?

9. Calculate the percentage composition of («) nitric
acid ; (b) potassium nitrate ; (c) sodium nitrate.

10. Calculate the percentage composition of («) alcohol
(C2H60); (6) acetic acid (C^O,); (c) cane sugar (CJH.OJ ;
(d) acetone (CgH6O).

11. Find the percentage composition of ether.

QUESTIONS AND OAL(TLATrONS 75

R ATOMIC AND MOLECULAR WEIGHTS

1. Suppose 10 g. of lead yield 14.642 g. of lead sulphate
(PbS04). Calculate the atomic weights of S on the assump-
tion that the atomic weights of lead and oxygen are 206.91
and 16 respectively.

2. A certain weight of copper oxide, when heated in a
current of H, lost 59.789 g. of 0 and formed 67.282 g. of
water. If 0 = 16, what is the atomic weight of H ?

3. One gram of a certain metal was dissolved in HC1
and gave 1242 cc. of H at 0° C. and 760 mm. The specific
heat was found to be 23. Calculate the equivalent weight
and the atomic weight. What would be the valence of the
metal ? the formula of the chloride ?

4. Suppose 13.67 g. of a compound of lead and oxygen
contained 12.39 g. of lead and 1.28 g. of oxygen ; what is
the formula of the compound if the atomic weight of lead
is 206.9 ?

5. If 63.8351 g. of silver iodide yield 38.9656 g. of silver
chloride, what is the atomic weight of iodine if 107.85 and
35.46 are accepted as the atomic weights of silver and
chlorine respectively ?

6. What is the equivalent of Ni if it dissolves in acids
with the evolution of a mass of H equal to 3.411 per
cent of its own mass ? What is its atomic weight if it is
bivalent ?

7. If the atomic weight of Ag is 197.94, and if the same
electric current, on passing through solutions of Ag and
Cu salts, precipitates weights of the metals in the ratio of
l(Cu) : 3.408 (Ag), what is the atomic weight of copper ?

8. The specific heat of P is 0.189 and its vapor density
referred to hydrogen is 62. How many atoms are there in
a molecule of phosphorus gas ?

76 REVIEW QUESTIONS AND PROBLEMS

9. Dumas synthesized silver sulphide (Ag.2S), finding the
ratio of the weights of silver and of the sulphide to be
112.1943 : 128.8288. The atomic weight of silver is 107.94 ;
find the atomic weight of S.

10. A chemist converted 16.6450 g. of bismuth oxide in-
to 25.2551 g. of bismuth sulphate (Bi2(S04)3). The atomic
weight of S is 32.06. Calculate that of bismuth.

11. Heinrichson heated 31.20762 g. of calcite and obtained
17.49526 g. of quicklime. If the atomic weights of oxygen
and carbon are 16.00 and 12.001 respectively, what is the
atomic weight of calcium ?

12. A chemist obtained from 59.4763 g. of magnesium
sulphate 19.9379 g. of magnesia. Calculate from this data
the atomic weight of Mg.

13. If 3.17 g. of iron form 4.53 g. of Fe2O8, what is the
atomic weight of iron ?

14. If 200 parts of BaCl2 give 224.2 of BaS04, what is
the atomic weight of barium ?

15. The molecular weight of lead oxide (PbO) is 221.3.
The per cent of lead is 92.81. Specific heat of lead is 0.031.
What is its atomic weight ?

16. The specific heat of Ag is 0.056. AVhat is its atomic
weight ?

17. If 4.5 g. of Hg unite with oxygen to form 4.86 g. of
mercuric oxide, and the specific heat of mercury is 0.032,
what is its atomic weight ?

18. A metal yields a chloride containing 66.14 per cent
of chlorine and having the specific gravity 7.44. What is
its atomic weight ?

19. Dumas found that 2.399 g. of aluminum chloride re-
quired 5.802 g. of silver for the complete precipitation of
the chlorine. Calculate the atomic weight of aluminum.

QUESTIONS AND CALCULATIONS 77

Calculate the molecular weights of the following :

20. NH4C1; (NH4)2C08; NH4HC08; (NH4)2Cr04; NH4CN;
NH4F; (NH4)2Mg04; NH4NO8; NH4NO2;

21. CaC08; CaAl204; Ca(HC08)2; CaO; Ca^lO^; CaF2;
Ca(OH)2; CaI2; CaS04; C02;

22. FeAs04.2H20; FeClg; FeC08; Fe804; FeS;

23. Pb(C2H802)2; Pb(B02)2.H20; PbBr2; Pb(N08)2;
PbO; Pb304;

24. MgF2; MgS04.7H2O; MnCl2; Mn(OH)2; HgCl2;
HgS04;

25. NiAs; NiCC^O,),; NiC08; HN08; N2; N2O; NOC1;

26. Sn02; Sn2Fe(CN)6; SnF2; SrBr2; SrC2;
H20; H2S04; SOBr2; TaBr5;

27. Mn208-H20; (CaBa)C08; CaC08(MgFe)C08;
(K2Ba) A^Sip^ ; (NaK) AlSig08.

C. SIMPLEST FORMULAS

1. Calculate the simplest formula for the compounds hav-
ing the percentage composition (a) N = 82.35, H = 17.64 ;
(b) N = 26.17, Cl = 66.35, H = 7.48.

2. Calculate the simplest formula for the substances hav-
ing the composition (a) 0 = 76.19, H = 1.58, N = 22.22 ;
(/>) N = 13.86, K = 38.61, 0 = 47.52.

3. Find the simplest formulas for the substances hav-
ing the following composition : (a) H = 1.58, N = 22.22,
0 = 76.19 ; (i) 0 = 47.53, N = 13.86, K = 38.61.

4. Calculate the simplest formula for the compounds hav-
ing the percentage composition : (a) N = 82.353, H = 17.647 ;
(b) 0 = 30, Fe = 70 ; (c) H = 1, C = 12, K = 39, O = 48.

5. What is the simplest formula for a compound having
the composition H = 7.69 and C = 92.3 ?

78 REVIEW QUESTIONS AND PROBLEMS

6. Calculate the simplest formulas for the substances
having the composition (a) C = 40, H = 6.67, 0 = 53.33 ;
(ft) C = 16.8, H = 5.26, N = 36.84, S = 42.1 ; (c) C = 54.55,
H = 9.09, 0 = 36.36.

7. Calculate the formulas for the following :

Cu = 34.46. CaO = 43.45. Ag = 53.15. Lithia=6.43.
Fe = 30.59. A1208 = 17.68. Cu = 31.08. Alumina = 29.26.
8 = 34.95. Si02 = 38.87. 8 = 15.77. Silica =64.31.

8. What is the simplest formula for a mineral whose
percentage composition is as follows: Ca, 50.12 per cent;
C, 12.04 per cent ; and 0, 47.84 per cent.

9. A liter of gas weighs 1.16 g. Is its formula CH, C2H2,
orC4H4?

10. The analysis of a certain compound gave the follow-
ing results :

1. C =12.00 2. 11.69 3. 11.83

H = 3.98 4.02 4.00

N = 6.77 6.80 6.78

Br = 77.56 77.61 77.64

What is its formula ?

D. MOLECULAR FOKMULAS

1. The vapor density of steam is 9. The percentage
composition of water is H = 11.11, 0 = 88.89. What is
the formula of steam ?

2. Find the formula for a hydrocarbon that contains an
equal number of hydrogen and carbon atoms, and the vapor
of which has a density (air) of 2.

3. If 750 cc. of CO weighs 0.94 g., what is the molecular
weight of the compound ?

ni KS'I 'IONS AND CALCULATIONS 79

4. Calculate the formulas for the compounds having the
following percentage composition and vapor density :

1. C = 92.3 per cent, H = 7.7 per cent, vapor den-

sity == 39.

2. C = 73.8 per cent, H = 8.7 per cent, N = 17.5 per

cent, vapor density = 80.2.

3. C = 39.9 per cent, H = 6.7 per cent, O = 53.4 per

cent, vapor density = 30.5.

4. C = 10.04 per cent, H = 0.84 per cent, Cl = 89.12

per cent, vapor density = 59.7.

5. The vapor density of Cl is 35.45. What is its molecular
weight ?

6. What is the formula for mercuric chloride as deduced
from the following data : weight of flask full of vapor at
350° and 758.4 mm. = 27.401 g ; capacity of flask = 250 cc. ?

7. The specific heat of P is, 0.189 and its vapor density
referred to H is 62. How many atoms are there in a mole-
cule of phosphorus gas?

8. The gas density of sodium vapor is 11.5. Calculate
the number of atoms in a molecule of sodium vapor.

9. A gaseous compound of H and C is found to contain
12 parts by weight of carbon to 1 part of hydrogen. Its
gas density is 13. What is its formula ?

10. If 1500 cc. of CO gas weigh 1.8816 g., what is the
molecular weight of the compound ?

11. Calculate the molecular formulas for the compounds
corresponding to the following data :

1. C = 73.8, H = 8.7, N = 17.1, vapor density = 5.03.

2. C = 92.3, H = 7.7, vapor density = 2.425.

3. C = 39.9, H = 0.7, 0 = 53.4, vapor density = 1.906.

Yapm- density in rach case is referred to oxygen.

80 REVIEW QUESTIONS AND PROBLEMS

12. An oxide of carbon contains 42.85 per cent of carbon.
Calculate the molecular formula if a liter of the gas weighs
1.25 g. under standard conditions.

13. A volatile liquid contains 37.5 per cent of carbon,
50 per cent of oxygen, and 12.5 per cent of hydrogen. A liter
of the vapor weighs about 16 times that of hydrogen. What
is the molecular formula ?

14. If a hydrocarbon contains 80 per cent carbon and a
liter of it weighs 1.346 g., what is its formula ?

15. Employ Avogadro's hypothesis in calculating the
atomic weight of oxygen from the following data : carbonic
acid gas, steam, laughing gas, and sulphurous anhydride con-
tain in the order named 72.73, 88.89, 36.364, and 50.00 per
cent by weight of oxygen ; and their densities referred to
H are, in the same order, 22, 9, 22, and 32.

16. A gas has the formula C3Hg. Is it lighter or heavier
than air ?

17. A liter of arsine weighs 3.49 g. under standard condi-
tions ; find its molecular weight.

18. What is the molecular weight of marsh gas, 3 1. of
which weigh 2.15 g.?

19. Calculate the molecular weights of the following gases
from their vapor densities : (a) chlorine, 35.5 ; (7>) hydro-
chloric acid, 18.25 ; (c) ammonia, 8.5 ; (<7) nitrogen, 1'4 ;
(e) steam, 9.

20. Sulphur dioxide is 2.22 times as heavy as air ; find
its density and the molecular weight.

21. The specific gravity of ammonia compared to hydro-
, gen is 8.5. What is its molecular weight ? Explain the

steps by which it is obtained.

22. At what temperature does air have the density of
H at 0°C.?

WEIGHTS AND VOLUMES FROM EQUATIONS 81

CHAPTER XXIV
WEIGHTS AND VOLUMES FROM EQUATIONS

1. What weight of hydrogen will be required for the com-
plete reduction of 10 g. of CuO ? What will be the volume
at a temperature of 15° C. and 740 mm. pressure ?

2. What weight of potassium chlorate (KC108) would be
needed to generate sufficient oxygen to fill a cylinder of
50 1. capacity under a pressure of 1000 cm. of mercury and
a temperature of 15° C. ?

3. The capacity of a balloon is 10,000 cu. ft. How much
would it cost to fill it with hydrogen at a pressure of 800 mm.
and at a temperature of 23° C., the H being made from Zn
costing 20 ct. per pound and sulphuric acid costing 8 ct.
per pound?

4. What weight of ammonium chloride will yield 1 1. of am-
monia at a pressure of 740 mm. and a temperature of 22° C. ?

5. What would be the volume under standard conditions
of a quantity of air that occupies 200 cc. at 20° C. under a
pressure of 740 mm. of mercury ?

6. How many liters of nitrogen monoxide can be prepared
from 100 g. of ammonium nitrate ?

'7. What volume of a solution of H2S04 that contains
40 g. of H2S04 in one liter will be required for the exact
neutralization of 10 cc. of a solution of NaOH containing
20 g. of NaOH to one liter ?

8. What volume of ammonia gas, temperature 20° C., pres-
sure 740 mm., can be obtained from 214 g. of sal ammoniac,
and how should one proceed to prepare it ?

9. How much sodic chloride may te formed from 10 g.
of crystallized sodic carbonate (NaaCO, • 10 H/)) ?

82 REVIEW QUESTIONS AND PROBLEMS

10. How much CO2 by weight and by volume can be ob-
tained from 53 g. of sodium carbonate ? What volume would
the gas occupy at 20° C. and 750 mm. pressure ?

11. Calculate the volume of C02 at 0°C. and 760mm.
that can be made from 50 g. of calcium carbonate and an
excess of HC1.

12. What volume will 25 kg. of oxygen occupy at a tem-
perature of 18° C. and a pressure of 740 mm.?

13. What weight of sulphur is necessary to produce 100 1.
of SO2 at a temperature of 20° C. and a pressure of two
atmospheres ?

14. How many cubic centimeters of H2SO4, containing
49 g. of H2S04 per liter, will be required to neutralize 2 g.
of NaOH ?

15. Find the number of grams of H2S04 required to unite
with 176 g. of iron sulphide to form H2S.

16. How many liters of oxygen at standard conditions
would be formed by the complete decomposition of 25 g. of
mercuric oxide ?

17. How many tons of oil of vitriol containing 70 per cent
H2SO4 are needed to convert 100 t. of salt into salt cake?

18. How much sulphuric acid and potassium nitrate
would be required to prepare 100 g. of HN08?

19. Compute the weight of KOH required for the exact
neutralization of the total quantity of HC1 obtained from
175.5 g. of NaOH by the action of H2S04.

20. A solution of 5 g. of potassium iodide is precipitated
with silver nitrate. W'hat will be the weight of the precipi-
tate of silver iodide ?

21. If sodium nitrate, ammonium nitrate, and potassium
nitrate were the same price per pound, which would be
cheapest to use for preparing nitric acid, and why ?

WEIGHTS AND VOLUMES FROM EQUATIONS 83

22. What relative weights of cupric oxide and cuprous
oxide are procurable from the same weight of copper ?

23. Compare the weights of aluminum and zinc necessary
for the production of equal weights of hydrogen by the
interaction with an acid.

24. What weight of H2S04 can be prepared from 100 g.
of sulphur ?

25. What weight of potassium bromate can be obtained
by neutralizing 1520 g. of bromine with potash ?

26. What weight of limestone is needed to convert 90 tons
of soda crystals into sodium bicarbonate ?

27. How many grams of CO2 will combine with 100 g. of
CaO to form CaCO8?

28. How much CaSO4 can be formed from 37 g. of CaCl2?

29. What weight of Al2Og will be needed to prepare 94.8 g.
of potash alum ?

30. What weight of sodium carbonate can be made from
500 kg. of common salt ?

31. Assume that thermit contains 75 per cent iron oxide ;
how much of the mixture would be required to produce 6 Ib.
of metallic iron ?

32. Find the oxygen necessary to burn 100 g. of CS2.

33. How many grams of iron sulphide are necessary to
prepare 100 1. of hydrosulphuric acid when the laboratory
conditions are 17° C. and the pressure 740 mm. ?

34. What weight of sodium chloride is necessary to pre-
pare sufficient hydrochloric acid to saturate 1 1. of water
under standard conditions ?

35. On the supposition that calcium carbide costs 12 ct.
a kilogram, what would be the cost of an amount suffi-
cient to generate 100 1. of acetylene measured at 20° C. and
TlOiiiiu.?

84 REVIEW QUESTIONS AND PROBLEMS

36. What weight of sodium carbonate crystals will 1 kg.
of the anhydrous salt yield ?

37. Write the equations for the preparation of 3 kg. of
KOH by three different methods.

38. Supposing bauxite to be aluminum hydroxide, what
weight of it is necessary for the prepai-ation of 100 kg.
of Al?

39. How much water is necessary to convert 50 g. of
P205 into hydrogen phosphite ?

40. How much carbon would be necessary to convert 50 g.
of CuO into pure copper ?

41. How much nitric and sulphuric acid is needed to pre-
pare nitric acid enough to exactly neutralize 5 Ib. of chalk ?

42. How many tons of coke containing 97 per cent carbon
are required to reduce 388 t. of hematite ?

43. In burning 27 g. of alcohol find the weight of the
products.

44. What weight of Cl can be prepared from 78 g. of rock
salt containing 99 per cent NaCI ? How much Mn02 and
H2S04 would be required to carry out the reaction ? What
volume would the Cl occupy under standard conditions, and
what volume of HC1 would be formed ?

45. How much metallic iron can be made by reducing
230 g. of ferric oxide ?

46. Calculate the volume of a solution of H2S04, den-
sity 1.8 and containing 89 per cent pure acid, that would
be required to make 200 g. of HC1 by acting on sodium
chloride.

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

MISCELLANEOUS QUESTIONS AND PROBLEMS 85

48. To neutralize completely 196 g. of H^SO^ what weight
of crystallized sodium carbonate (Na2C08 • 10 H20) is re-
quired ? The volume of C02 evolved is approximately 4450 cc.
under standard conditions. Calculate its volume at 890 mm.
pressure and 27° C.

49. What volume of nitrous oxide (N20) measured at
0° C. and 750 mm. would be evolved by the decomposition
of 10 g. of ammonium nitrate, assuming the weight of 1 1. of
nitrous oxide at 0° C. and 760 mm. to be 1.97 g. ?

CHAPTER XXV
MISCELLANEOUS QUESTIONS AND PROBLEMS

1. Mention the constituents of water and give their
properties by volume and by weight. Compare them as to
physical and chemical properties.

2. State and illustrate the Law of Multiple Proportions.

3. Find the percentage composition of H2S04. How
many grains of SO2 can be set free by the action of 325 g.
of the acid on copper ?

4. Describe the usual methods of preparing ammonia on
a commercial scale. Write the equation.

5. Describe an experiment illustrating the bleaching
properties of S02. Explain.

6. Distinguish between («) allotropism and isomerism;
(ft) efflorescence and deliquescence ; (c) hard and soft water.

7. Mention three distinct allotropic forms of carbon.
Compare the physical properties of the forms mentioned.

8. Describe a method of manufacturing matches. Write
two reactions that take place when a common friction match
is ignited.

86 REVIEW QUESTIONS AND PROBLEMS

9. Distinguish between (a) a physical change and a
chemical change ; (&) between a mixture and a chemical
compound; (c) illustrate each.

10. Mention the constituent metals of these alloys : bell
metal, pewter, brass, soft solder, German silver, type metal,
Babbitt metal.

11. Write the chemical name of each: white lead, blue
vitriol, calomel, gypsum, caustic potash, copperas.

12. Describe a method of preparing phosphorus and write
the reactions. %

13. Find the weight of the products of combustion when
26 g. of alcohol (C2H60) are burned.

14. Write the graphic formula of hydrogen arsenide and
the reaction for its complete combustion.

15. Describe an experiment to show that a metal changes
in weight when heated in air. Explain.

16. What is a solution ? Describe an experiment to illus-
trate (a) a saturated solution ; (A) a supersaturated solution.

17. Describe a method of preparing nitrogen and make a
sketch of the apparatus. Give the important physical and
chemical properties of N.

18. Give the important physical and chemical properties
of bromine. Mention one source and two uses of bromine.

19. Describe a test to show the presence of each of the
following : oxygen, iodine, sodium, carbon dioxide, lead.

20. A liter of gas under standard conditions weighs
2.0608 g. Find (a) its vapor density ; (7>) its molecular
weight.

21. Name four important constituents of the air and give
the relation of each to plant and animal life.

22. Describe the preparation of nitrous oxide, writing
the reaction, and give the important properties.

MISCELLANEOUS QUESTIONS AND PROBLEMS 87

23. Describe the process by which the pig iron of com-
merce is obtained from the ore by means of a blast furnace.

24. Name the four most important constituents of ordinary
illuminating gas. Give the relative importance of these
constituents in the production of (a) light; (6) heat.

25. Describe the Bessemer process of manufacturing steel
and make a tabular statement of the physical and chemical
difference between wrought iron and cast iron.

26. What substance did you employ in the laboratory
preparation of hydrochloric acid ? Why was each substance
selected ?

27. Describe the action and explain what occurs when
chlorine water is added to a solution of potassium iodide
containing starch.

28. Give three methods for collecting gases and state
the conditions under which each may be advantageously
employed.

29. How many cubic centimeters of H2SO4, containing
49 g. per liter, will be required to neutralize 2 g. of sodium
hydroxide ?

30. Describe the preparation of hydrogen gas and make
a sketch of the apparatus used. How can it be proved ex-
perimentally that water is formed when H burns ?

31. («) How is coal gas manufactured ? (£) How could
you show by experiment that particles of solid carbon are
present in a luminous flame of coal gas ? (c) Why is a
Bunsen flame nonluminous ?

32. Describe the process by which metallic aluminum is
manufactured. Describe the reaction that takes place be-
tween metallic aluminum and ferric oxide when a mixture
of the two is ignited. What practical applications are made
of this reaction ?

88 REVIEW QUESTIONS AND PROBLEMS

33. What is meant by the term " catalysis " ? tfame three
processes or reactions where a catalytic agent is present.

34. Describe the essential features of the mechanical fil-
tration process for the purification of large water supplies.

35. What occurs when a solution of copper sulphate is
electrolyzed (a) with both electrodes of platinum ? (i) with
both electrodes of copper? Describe the electrolytic puri-
fication of crude copper.

36. Define basic anhydride and acid anhydride; give an
example of each. What is a dibasic acid ? Give examples.

37. Describe in detail the Le Blanc process for the
manufacture of soda.

38. Discuss the periodic classification of the elements.

39. Explain briefly two practical methods of determining
the combining weights of oxygen and hydrogen.

40. How may lime be shown to be the oxide of a metal ?

41. How may sulphuretted hydrogen be made? Give
the properties and uses of this substance.

42. What is soap ? How is it made ? What is the
difference between hard soap and soft soap ?

43. Name three substances occurring in nature that are
composed of calcium carbonate. What substances are formed
when calcium carbonate is highly heated ? What change
takes place when water is added to the solid product thus
formed ? What use is made of the latter substance ? What
chemical change occurs when it is exposed to the air ?

44. What is plaster of Paris ? What chemical difference
is there between the hardening of mortar and the setting
of plaster of Paris ?

45. State by what experiments you could find out whether
or not a compound (a) contains water of crystallization;
(i) is efflorescent ; (c) gives ions in dissolving ; (d) is an acid.

MISCELLANEOUS QUESTIONS AND PROBLEMS 80

46. What experiments should you make to distinguish
between (a) magnesium oxide and flour? (7>) potassium
chloride and potassium bromide ?

47. State the practical use and explain the efficiency of
the Davy safety lamp.

48. Mention the chemical name and write the formula of
each of two oxides of phosphorus, and describe a method
of preparing each.

49. Define kindling temperature. Mention, in the order of
their kindling points, charcoal, sulphur, coal, phosphorus.

50. Describe, writing the reactions, a method of preparing
ammonia by the action of an alkali on an ammonium salt.

51. Define and illustrate filtrate, reagent, triad, halogen,
positive element, hydroxide, isomerism.

52. Distinguish in meaning between the following suffixes
when used in names of chemical compounds : (a) ous and
ic : (£») ite and ate ; (c) and the prefixes hyjjo and per.

53. Find under standard conditions the weight of 1 1.
of CO.

54. Define fermentation. Describe a laboratory experi-
ment to illustrate fermentation, writing the reactions.

55. Describe the occurrence of S in nature. Describe the
process of extracting sulphur from one of its ores.

56. Describe the manufacture of safety matches and state
why they are safer than other matches. Write the chemical
reactions that occur when safety matches are ignited.

57. Describe the process of extracting mercury from one
of its ores, writing the reaction. Mention the important
physical properties and the principal uses of mercury.

58. In what compound does chlorine usually occur in
nature (give chemical and common name)? Show by equa-
tion how free chlorine is obtained from this body.

90 REVIEW QUESTIONS AND PROBLEMS

59. How is sulphur dioxide made from sulphur and how
is sulphuric acid made from it ? Write equations.

60. Show by equations how calcium carbonate decom-
poses on heating and how it reacts with dilute H2SO4. Give
the common names of the products of both reactions.

61. Point out the chemical similarity between chlorine,
bromine, and iodine. What is this group called ? How is
each of these elements set free from a salt containing it ?

62. Give the Laws of Definite and Multiple Proportion
and point out what relation they have to the atomic theory.

63. What is the basis of the Mendeleeff classification ?
What evidence have we that this is a natural classification ?
Discuss the properties of the elements in some natural family
in such a way as to show their apparent relation.

64. Define the terms " atom," " valence," " equivalent,"
and " gram-molecule." Explain the following processes : dis-
tillation, sublimation, electrolysis, neutralization, reduction,
fermentation, precipitation ?

65. To what constituents do acids owe their characteris-
tic properties ? Does this substance impart these proper-
ties to all its compounds ? What is the theory advanced to
explain the facts embraced in your answer? How do we
explain the fact that some acids are stronger than others ?
Name some other facts which the above-mentioned theory
explains.

66. One volume of oxygen at 100° C. will go to form how
many volumes of steam under the same conditions ? How
will the number of molecules of each compare ? What in-
ference can be drawn from the last answer as to the char-
acter of the oxygen molecule ? How do we account for
the increase in the density when oxygen is converted into
ozone ?

MISCELLANEOUS QUESTIONS AND PROBLEMS 91

67. Give an account of the manufacture of H2S04. Write
the equations. How are the pan acid and concentrated acid
obtained from the chamber acid? Give the uses to which
this acid is put.

68. Define the terms " acid," " base," and " salt." Discuss
the process of neutralization. What is the modern concep-
tion as to the condition of acids, bases, and salts in dilute
aqueous solutions ?

69. Describe the Solway process for the manufacture of
soda, giving the reactions.

70. State the Law of Gay-Lussac and the hypothesis of
Avogadro, and illustrate each.

71. Give the principal sources and the chemical and phys-
ical properties of the following elements : hydrogen, sulphur,
nitrogen, carbon, sodium, and zinc.

72. How much metallic iron can be obtained by reducing
23 g. of ferric oxide ?

73. If a quantity of steam which, at 100° C. and standard
pressure, occupies 500 cc. be cooled to 4° C., what will be
the volume of its resulting water ? What will it weigh ?

74. Give the properties of sodium, potassium, copper,
lead, and phosphorus, and the equations for the preparation
of each.

75. Describe the manufacture of white lead, the making
of caustic soda, or the refining of copper.

76. Are the reactions reversible by which («) oxygen
is obtained from potassium chlorate ? (i) ^hydrogen from
sodium and water ? (c) water from oxygen and hydrogen ?
Why?

77. When dilute acid is poured on zinc, what causes the
reaction to go in one direction only ? If H dissolved abun-
dantly in water, how far would the reaction go ?

92 REVIEW QUESTIONS AND PROBLEMS

78. Is the burning of a candle a reversible reaction that
runs to equilibrium ? Why ?

79. Thin layers of oxides form over the surfaces of most
metals, making soldering impossible. The tinsmith makes
firm joints by using acid or rosin when soldering. Explain
the action.

80. Experiments show that 13.1 g. of zinc unite with 32 g.
of oxygen to form zinc oxide. Calculate the combining
weight of zinc.

81. Name the following compounds and write the formulas:

1. The magnesium salt of chloric acid.

2. The zinc salt of chlorous acid.

3. The calcium salt of nitrous acid.

4. The potassium salt of hypochlorous acid.

5. The sodium salt of carbonic acid.

6. The lithium salt of perchloric acid.

7. The mercurous salt of nitric acid.

8. The mercurous salt of nitrous acid.

9. The mercuric salt of nitric acid.

10. The compound of sodium and hydrogen.

11. The compound of aluminum and silicon.

12. The two compounds of tin and sulphur.

82. 1 g. of aluminum acted on by acid yields 1230 cc. of
H under standard conditions. Calculate the apparent com-
bining weight of Al, and correct this by the use of Dulong
and Petit's Law, the specific heat of Al being 0.22.

83. What is a flame ? What causes the luminosity of a
flame ? Why is the Bunsen flame nonluminous ? Describe
the structure of the Bunsen flame.

84. State Avogadro's hypothesis and illustrate it by
means of the union of H and 0 to form water, and of Cl
and H to form HC1.

MISCELLANEOUS QUESTIONS AND PROBLEMS 93

85. A solution of potassium permanganate undergoes no
change when a current of hydrogen gas is caused to bubble
through it. It is soon decolorized, however, after treatment
with zinc and sulphuric acid. Explain fully the principle
underlying these facts.

86. What is ozone? How may it be prepared? What are
its properties ? What is hydrogen peroxide ? What are its
properties ?

87. What advances of practical importance have resulted
from the study of chemistry and from chemical investigation ?

88. How is ammonia used in refrigeration ? How do you
class the radical NH4 ?

89. Give the formula and properties of acetylene and
describe a method by which it may be made.

90. The atomic weight of carbon is 12 and of oxygen
15.9. What is the weight of 1 1. of a gas of the formula
< J 1 ,. < M ),. < '< ), C2H2 ? What volume of 0 will be necessary
for the complete combustion of 1 1. of each of these gases ?
Give equation in each case.

91. Give the equations illustrating the formation of HaSO4
from sulphur dioxide, air, steam, and the oxides of nitrogen.
State the properties of concentrated sulphuric acid.

92. A piece of calcium chloride becomes moist after pro-
longed exposure to the air. A clear crystal of sodium sul-
phate loses its transparency and crumbles to powder after
a similar exposure. Explain the principle underlying these
facts, and define the terms used to characterize the proper-
ties illustrated by them.

93. Calculate the approximate weight in grams of 1 1. of
each of the following gases: HC1, C12, HI, NH3.

94. How may CO2 be prepared ? Through what cycle does
carbon pass in animal and vegetable life?

94 REVIEW QUESTIONS AXD PROBLEMS

95. Define distillation, filtrate, titration, standard solu-
tion, catalysis, indicator, polymerization, alkali, neutral
reaction, halogen.

96. Explain the term " ion " and " ionization." What
classes of substances are ionized when dissolved in water ?
By what are all such substances designated ? Define acid
and base in terms of the theory of electrolytic dissociation.

97. Write the equation for preparing hydrofluoric acid
and explain the process of etching on glass.

98. Give a brief account of the discovery of any one of
the chemical elements, including the name of the discoverer
and the approximate date and conditions of discovery.

99. What is the formula for white arsenic ? What com-
pound of arsenic is formed when a solution of the substance
is brought together with zinc and sulphuric acid ? Why is
the compound not formed when hydrogen gas is led through
the. solution ?

100. In what great industry is calcium phosphate (normal)
employed? To what treatment must it first be subjected ?

101. Name an important ore of lead. Describe a method
of extracting lead from the ore mentioned, and mention two
practical uses of lead.

102. Give a brief account of the alkaline-earth metals.
Tell how glass is made and colored.

103. State the general difference between metals and non-
metals. What is a heavy metal ?

104. Is the process of oxidation accompanied by the
process of reduction ? Illustrate by an equation and inter-
pret. Is occlusion a chemical or a physical action ? State
your reasons.

105. A gas globe when full of air weighed 55.06 g., and
when full of water at 20° C. it weighed 309.66 g. The air

MISCELLANEOUS QUESTIONS AND PROBLEMS 95

•was removed from the globe and the latter carefully weighed
by means of a counterpoise. The globe was then filled with
a gas at 19.8° C. and 761.4mm., when it weighed .469 g.
more than when the air was exhausted. What is the weight
of a liter of this gas under standard conditions ?

106. How many cubic centimeters of water will have to
be added to 10 g. of H2S04 to yield a 10 per cent solution
of the acid?

107. What is the heat of formation of sulphuric acid
from its elements in a dilute aqueous solution ?

108. Calculate the percentage composition of garnet
(<VV'(Si°4)i); of mica (KH2Al8(Si04)8).

109. How much does a mole of sulphuric acid weigh ? of
sodium chloride ? of ammonium nitrate ?

110. A compound of hydrogen and carbon of exactly the
same percentage composition has the gas density of 39.
What is its formula?

111. In the preparation of phosphine what gases may
take the place of hydrogen ?

112. What is a mineral? Are the following substances
minerals : quartz, water, granite, mercury, soil, coal oil ?

113. What other elements besides aluminum act either
as acid formers or as base formers ?

114. What substances must be avoided when galvanized-
iron vessels are in use ?

115. Why is nitric acid a better solvent for Hg, Cu, and
Ag than hydrochloric or sulphuric acid ?

116. A silver dollar contains 10 per cent alloy and weighs
26.5 g. How much is the silver in it worth ? How could
you separate it from the copper ?

117. Prove that the phosphorus molecule has 4 atoms.

96 REVIEW QUESTIONS AND PROBLEMS

118. Reduce the following to the Fahrenheit scale:
(«) + 3o°C.; (&) +89°C.; (c) - 40° C. ; (d) - 50° C. ;
(«) + 104°C.

119. Reduce the following to the centigrade scale:
(a) 38° F.; (ft) 120° F.; (c) - 64° F.; (rf) -30°F.; (e) 0°F.;
(/) - 40° F.

120. Outline the contact and the lead-chamber processes
of manufacturing H2S04, and compare them as to efficacy.

121. Prepare a, table of the halogens according to the
following form:

1. Element.

2. Atomic weight.

3. Compounds found in nature (formulas).

4. Equations for the preparation of the element.

5. Physical properties.

6. Chemical properties.

7. Relative replacing power.

8. Equations for the preparation of the hydrogen

compound.

9. Stability of the hydrogen compound.

122. What are the speeds of transpiration of ammonia
and nitrogen ?

123. Name three substances — one gas, one liquid, and one
solid — that are used for disinfecting and that have bleach-
ing properties. Explain the action of each in bleaching.
State the advantage of formaldehyde for fumigation.

124. In what liquid is sodium usually kept ? How are red
and yellow phosphorus usually kept ? Explain.

125. Give Avogadro's Law and find how many cubic feet
of CO are represented in the following reaction if there
are represented 10 cu. ft. of C02, all volumes at the same
temperature and pressure,

PROBLEMS 97

CHAPTER XXVI

PROBLEMS ON MEASUREMENT, TEMPERATURE,
WEIGHT, AND DENSITY

A. MEASUREMENT

1. Find the number of liters in a cubic meter; the
number of cubic millimeters.

2. How many millimeters in («) 16km.? (b) 21Hm.?
(c) 26.9m.? (d) 66.92dm.? (e) 108.2cm.?

3. How many feet in 62.14 m. ? in 390 m. ?

4. Convert 43 in. into (a) decimeters ; (6) hectometers ;
(<;) kilometers ; (</) centimeters ; (e) millimeters.

5. Calculate the number of liters necessary to fill with
water a tank 21 x 60 x 8 ft. in dimension.

6. Required the number of square millimeters, square
centimeters, square decimeters, contained in the top of a
flat desk measuring 1 in. 20 cm. by 80 cm.

7. How many miles in 15km.?

8. A room 20 m. x 50 m. x 3m. is filled with air under
standard conditions. How many liters are there ? How
much does it weigh in kilograms ?

9. A woodpile containing 1500 m.8 is 12 m. long and
12 m. wide. How high is it ?

10. What is the capacity of a tank in liters that is
4 m. x 9 m. x 8 m. in dimension ?

11. What is the radius in centimeters of a sphere whose
volume is measured by 6 1. of water ?

12. How deep must a cistern be to hold 80001., if the
bottom lias a radius of 1.75m.? How deep if it has a
square bottom 3m. on a side?

98 REVIEW QUESTIONS AND PROBLEMS

13. A rectangular scow 40m. long and 7m. wide draws
1 in. of water when empty and 3 in. when loaded ; find in
kilograms the weight of the load.

14. How many liters will a cylindrical gasometer 1 in.
across and 15 m. high hold ?

15. A pressure of 1000 Ib. per square inch is how many
kilograms per square millimeter ?

B. TEMPERATURE

1. Convert into the centigrade scale :
(a) 36° R.; (b) 28° R.; (c) 76° R.

2. Convert into the Reaumur scale :
0)90°C.; (7»)15°C.; (c) 55°C.; (d) 30° C.

3. Convert into the Fahrenheit scale :

(a) 52° R.; (b) 76° R.; (c) 6.7° R.; (d) 25° R.

4. Convert into the Reaumur scale:

(a) 48° F.; (b) 129° F.; (c) 210° F.; (d) - 30° F.

5. Convert into the centigrade scale :

(a) 207° F.; (ft) 180° F.; (c) 0°F.; (d) -30°F.

6. Convert into the Fahrenheit scale :

(a) 643° C.; (b) 972° C.; (c) -40°C.; (rf) 2500° C.

7. Convert into the absolute scale :

(a) 8°C.; (b) 40°C.; (c) 80°C.; (d) 2000°F.; (e) - 37°F.

8. Convert into centigrade, Reaumur, and Fahrenheit

scales :
(a) 400° and (V) 267° absolute scale.

C. WEIGHT AND DENSITY

1. How much space will 4320 g. of water occupy ?

2. What is the weight of water in a tank 20 cm. x
31cm. x 92cm.?

3. A mass of 63 g. is divided into pills 7 in number.
What is the weight of each ?

I'KOIJLKMS 99

4. If a liter of Hg. weighs 13 kg. 598 g., find the weight
in kilograms of 4.2 1.

5. A cubical block of wood 2 cm. on a side weighs 5 g.
How far will it sink in alcohol of specific gravity .8 ?

6. If the density of brass is 8.5, what will be the weight
in air of a mass of brass which weighs in vacua 500 g.?

7. A liter flask weighs 25 g. When filled with a mixture
of alcohol and water it weighs 867 g. How many cubic
centimeters of each in the flask ?

8. A piece of cork floats on ether with 12 cc. exposed.
What is the entire volume of the cork?

9. The pressure of the air will hold water 30 ft. high in
a vacuum. How high will it hold mercury ?

10. If a pint of water weighs exactly a pound, how many
cubic inches would it contain ?

11. A lump of metal weighs a ton. Its weight in water
is 1500 Ib. What is its specific gravity ?

12. Find the mass of 50 cc. of benzine if its density = 0.85.

13. A piece of lead weighed 39.9 g. in air and 36.368 g.
in water. What is the specific gravity of lead ?

14. Find the volume of 1000 g. of sea water.

15. Find the specific gravity of alcohol from the follow-
ing data :

1. Weight of specific-gravity bottle empty, 20.3920 g.

2. Weight of specific-gravity bottle filled with water,

70.3412 g.

3. Weight of specific-gravity bottle filled with alcohol,

61.6515 g.

16. A piece of lead weighs 50 g. in air, and when sus-
pended in a liquid whose specific gravity is 1.2 it weighs
44.69. Determine the specific gravity of lead.

100 REVIEW QUESTIONS AND PROBLEMS

17. If sulphuric acid has a specific gravity of 1.84, how
many cubic centimeters of it weighs 80 g. ?

18. Nitric acid is 1.52 times as heavy as water. What is
the weight of 3 1. of the acid ?

19. A balloon contains 1000 cu. m. of a gas whose density
is 0.000092 g. per cubic centimeter. Taking the density of
air as 0.0003 g. per cubic centimeter, calculate the total
weight which the balloon will lift.

20. A block of wood having a cross section of
5 cm. x 4 cm. x 3 cm. floats in water when immersed to a
depth of 2.5 cm. What mass of lead on the top would be
sufficient to cause complete immersion of the block ?

21. A piece of metal weighs 50 g. in air, and when sus-
pended in a liquid whose specific gravity is 1.2 it weighs
44.6 g. What is its specific gravity and what metal is it ?

22. What is the weight of ammonia and of chlorine
necessary to produce 1 1. of nitrogen ?

23. Calculate the specific heat of iron from the follow-
ing data:

1. Weight of iron used, 100 g.

2. Weight of ice melted, 14.35 g.

3. Temperature of the iron at the beginning of the

operation, 100° C.

4. Latent heat of water, 80.

24. How many cubic centimeters of a liquid of specific
gravity 1.4 must be mixed with 1 1. of a liquid of specific
gravity .8 to make a mixture of specific gravity 1.2 ?

25. A capillary glass tube weighs .2 g. A thread of mer-
cury 12 cm. long is drawn into the tube, when it is found to
weigh .7 g. Find the diameter of the capillary tube.

26. Find the length of an iron rod 2 cm. in diameter
that weighs 1 kg.

PROBLEMS 101

27. If gold were bought in Alaska at a certain price per
ounce, and sold in Mexico at the same price, would there be
a gain or loss, transportation charges not being considered ?

28. A quantity of silver when placed in one pan of an
untrue balance appeared to weigh 5 gm., but when placed
in the other pan 6 gm. What is the true mass of the silver ?

APPENDIX

CHAPTER XXVII

I. PHYSICAL CONSTANTS OF THE IMPORTANT
ELEMENTS1

ELEMENT

SYMBOL

ATOMIC
WEIGHTS

VALENCE

SPECIFIC
GRAVITY

MEI.T-

PolXT

BOIL-
ING

POINT

Ap-

proxi-
mate

Exact

Water

Air

Aluminum . .

27.

27.1

III

2.6

657.

1500.

Antimony . .

si,

120.

120.2

6.6

630.

1500.

Argon

40.

39.9

1.38

-188.

-186.

Arsenic

75.

III.V

5.7

360.

Barium ....

137.

137.4

3.8

850.

950.

Bismuth. . . .

208.

III.V

9.7

269.

1435.

Boron

11.

III

2.6

infus.

3500.

Bromine. . . .

80.

79.96

3.1

-73

59.

Cadmium . . .

112.

112.4

8.6

322.

778.

Calcium ....

40.

40.1

800.

Carbon

12.

1.7-2.1

subl.

3500.

Chlorine. . . .

35.5

35.45

2.49

-102.

-33.6

Chromium . .

52.

52.1

II, III, VI

6.9

1515.

Cobalt

59.

8.7

1530.

Copper

63.6

1,11

8.9

1065.

2100.

Fluorine. . . .

19.

1.31

-223.

-187.

Gold

197.

197.2

I, III

19.3

1065.

Helium

0.13

-271.

-267.

Hydrogen. . .

1.008

0.07

-256.5

-2525

Iodine

127'.

126.9

4.9

114.

184.

Iron

56.

58.9

n, in

7.8

1950.

Lead

207

2069

II IV

11.3

327

1400.

Lithium ....

7.03

059

186.

1400.

Magnesium .

24.3

1.7

632.

1100.

Manganese. .

55.

II, IV

7.4

1245.

Mercury ....

200.

1,11

13.6

-38.8

357.

Nickel

58.7

8.7

1484.

Nitrogen . . .

14.

III.V

0.96

-210.

-195.

Oxygen

ie!oo

1.10

-230.

- 182.

Phosphorus .
Platinum . . .

31.
195.

31.

194.8

IILV
IV

1.8
21.5

44.2
1710.

290.

Potassium . .

39.

39.1

0.87

625

757.

Silicon

28.

28.4

2.0

3500.

Silver

108.

107.9

105

961.

2050.

Sodium ....

23.05

057

97.6

877.

Strontium . .

8?!

87.6

900.

Sulphur ....
Tin

S
Sn

33.
119.

32.06
119.0

II, IV, VI

h,iv

2.0
73

1145
232.

444.6
1600.

Zinc

•/.n

65.

65.4

7.1

419.

918.

1 This table will be found in the text of Brownlee and others, and is used by
their permission.

104 REVIEW QUESTIONS AND PROBLEMS

II. WEIGHTS AND MEASURES

LENGTH

1 millimeter (mm.)
1 centimeter (cm.)
1 decimeter (dm.)
1 meter (m.)
1 kilometer (km.)

= 10 mm.
= 10 cm.
= 10 dm.
= 1000 in.

= 0.03937 inch
= 0.3937 inch
= 3.937 inches
= 39.37 inches
= 0.6214 mile

VOLUME

1 cubic centimeter (ccm.) = 0.06103 cubic inch

1 cubic decimeter = 1000 ccm. = 61.03 cubic inches
1 liter (1.) =1000ccm. = 1.057 quarts

1 cubic meter =10001. =35.32 cubic feet

WEIGHT

1 milligram (mg.) = 0.0154 grain

1 gram (g.) = 1000 mg. = 15.432 grains

1 kilogram (kilo), kg. = 1000 g. = 2.2046 pounds av.

III. TABLE OF METRIC TRANSFORMATION

To <:n.\ M; i:

Inches to centimeters .
Centimeters to inches .

MULTIPLY BY
. 2.54
0.3937

Cubic inches to cubic centimeters . . .« 16.387

Cubic centimeters to cubic inches 0.061

Ounces to grams (avoirdupois) 28.35

Grams to ounces (avoirdupois) 0.0353

Grains to grams 0.0648

Grams to grains 15.43

APPENDIX

105

IV. WEIGHT OF ONE LITER OF VARIOUS GASES

MEASURED UNDER STANDARD

CONDITIONS

Air

. . 1.2023

Oxygen

1 430

Ammonia ....

. . 0.7(il7

Hydrogen

. 0.08984

Carbon dioxide . .

. . 1. '.IIJ41

Hydrosulphuric acid

. 1.5211

Carbon monoxide .
Chlorine ....
Cyanogen . '. . .

. . 1.251
. . 3.1650
. . 2.322

Methane . . . . .
Nitric oxide ....
Nitrogen

. 0.7157

. i.slto

1 2501

Ethylene ....

. . 1.252

Nitrons oxide . . .

. 1.9677

Hydrazoic acid . .
Hydrocyanic acid .

. . 1.920
. 1.2036

Sulphur dioxide . .
Steam .

. 2.8596
0.805

V. PHYSICAL FORMULAS
TEMPERATURE

BOYLE'S AND CHARLES'S LAWS COMBINED

(«)r =

-a)

760° [1 + (.003660]

T'P

VI. SPECIFIC GRAVITIES

Brass

8.4

Nitric acid

1 56

Cork

0.25

Silver

. . 10.5

Coal

1.8

Sulphuric acid . .

. . 1.84

Gold

19.8

Tin ,

. . 7.3

Hydrochloric acid . . .

1.22

Water (distilli-d) .

. . 1.

Iron

7.8

Water (sea) ...

. . 1.025

Kcrosr-iH'

0.8

Water (ice) . . . ,

0.92

Lead

11.3

Zinc

7.1

106

REVIEW QUESTIONS AND PROBLEMS

2 3

UNIVERSITY OF CALIFORNIA AT LOS ANGELES
THE UNIVERSITY LIBRARY

This book is DUE on the last date stamped below

MAY 9

0V 16 1939
w 3 1940

JAN 3 0 1947
APR 22

194-

194C

MAR 1 7 1943

**& 1 7 1Q49

Form L-9-15m-3,'34

FEBl

-RHTDCOLLIB.

NOYlOK
(

OCTs

.0^0

UNIVERSITY o:

LOS ANGELES
LIBRARY

1158 00396 2346

DC SOUTHERN REGIONAL LIBRARY FACIL

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