Question

Kjeldahl's method was used for the estimation of nitrogen in an organic compound. The ammonia evolved from $0.55g$ of the compound neutralised $12.5mL$ of $1M{H}_{2}S{O}_4$ solution. The percentage of nitrogen in the compound is ______(Nearest integer)

Answer 1

Answer: 64

Meq of $H_{2}S{O}_4$ used by $N{H}_3=12.5\times 1\times 2=25$
$\%$ of $N$ in the compound $=\frac{25\times 10^{-3}\times 14\times 100}{0.55}=63.6$ or
Meq. of $H_{2}S{O}_4=$ Meq. of $N{H}_3$
12. $5\times 1\times 2=25$ meq. of $N{H}_3$
$=25$ millimoles of $N{H}_3$
So Millimoles of ' $N$ ' $=25$
Moles of ' $N^{\prime }=25\times 10^{-3}$
wt. of $N=14\times 25\times 10^{-3}$
$\%N=\frac{14\times 25\times 10^{-3}}{0.55}\times 100$
$=63.66$
$\approx 64\%$