Question

0.7g of `(NH_(4))_(2)SO_(4)` sample was boiled with 100mL of 0.2 N NaOH solution was diluted to 250 ml. 25mL of this solution was neutralised using 10mL of a 0.1 N `H_(2)SO_(4)` solution. The percentage purity of the `(NH_(4))_(2)SO_(4)`sample is :
A. 94.3
B. 50.8
C. 47.4
D. 79.8

Answer 1

Correct Answer - A
meq.of `NH_3=10`
m.mole of `NH_3=10`
m.mole of `(NH_4)_2SO_4=5`
wt.of `(NH_4)_2SO_4=5/1000xx132=0.66` gm
% of `(NH_4)_2SO_4=0.66/0.7xx100=94.28%`