E AGRICULTURAL ANALYSIS

2. A solution of hydrochloric acid was standardl^0^ by
precipitating the chlorine from 40 cc as silver chloride.

weight of silver chloride found was 0.6327 gm. Required

normality of the solution.

• i i j- 0.6327 ., ul . ,

1 cc acid solution =c= — TTT™ gm silver chloride*

1 cc normal acid solution =c= 0.1433 gm silver chloride-
Therefore normality- ^fUo.I433 =40^^33 -O.HO7N.

To make the solution decinormal 1000 cc would be diluted to
1107 ec.

3. A similar solution was standardized by titration of pure
sodium carbonate in presence of methyl orange, the following

reaction being completed:

NajCOa + 2HC1 ->2NaCl + H2COS.
It was found that 32.2 cc acid =c= 0.1638 gm of the primary

standard, sodium carbonate. Required the normality.

., 0.1638 ,. , , , •

1 cc acid =£= -n-n' gm sodium carbonate and

1 cc normal acid =c= 0.053 gin sodium carbonate.

Therefore normality = 32y^fo53= °-9598 N-

4. Another acid solution was standardized by titration against
a measured volume of standard potassium hydroxide solution
in presence of methyl orange according to the equation :

One cubic centimeter of the primary standard contained O.OO468
gm of potassium hydroxide. It was found from the ti tra/tion
that 50 cc of potassium hydroxide solution o: 43.5 cc of
hydrochloric acid solution.
The weight of potassium hydroxide in 50 cc of solution =
50 X 0.00468 gm. Since this weight was equivalent to -43.5
cc of acid, the potassium hydroxide equivalent to 1 cc sicici =
50 X 0.00468
-jg~ -------- gm. Ihe normality of the hydrochloric acid, solu-
50 X 0.00468
43.5 x