Question

During nitrogen estimation of an organic compound by Kjeldahl's method, the ammonia evolved by 0.5 g of the compound neutralised 10 ml of 1 M $H_{2}S{O}_4$. Calculate the percentage of nitogen in the compound.

• A. 50 %
• B. 60 %
• C. 56 %
• D. 66 %

Answer 1

The correct option is C 56 %

Mass of organic compound= 0.5 g
Volume of 1 M $H_{2}S{O}_4$ required=10 ml
$\therefore 10ml$ of 1 M $H_{2}S{O}_4$=20 ml of 1 M $N{H}_3$
Now 1000 ml of 1 M $N{H}_3$ contains 14 g N
$\therefore$ 20 ml of 1 M $N{H}_3$ would contain$=\frac{14}{1000}\times 20$
$\therefore$ Percentage of N$=\frac{14\times 20}{1000}\times \frac{100}{0.5}=56\%$