Question

During estimation of nitrogen present in an organic compound by Kjedhal's method, 0.17 g of $N{H}_3$ was evolved from 0.28 g of a nitrogenous compound. What is the percentage of nitrogen in the organic compound?

• A. 5
• B. 30
• C. 50
• D. 80

Answer 1

Answer: (C)

50

$\%N=1.4\times \frac{\text{m.eq. of}{H}_{2}S{O}_4\text{used to neutralise}N{H}_3}{\text{Mass of compound.}}$

$=1.4\times \frac{x}{0.28}$

$x=$ m.eq. of $H_{2}S{O}_4$ used to neutralize $N{H}_3$.

100 meq. on 1000 ml of M $N{H}_3$ contains $=17$ gm. of $N{H}_3$

Moles of $N{H}_3=\frac{0.17}{17}=0.01$

$\therefore$ m.eq of $H_{2}S{O}_4=0.01\times 1000=10=x$

$\%N=1.4\times \frac{10}{0.28}=50$
Option C is correct.