Question

$0.5$ g of an organic compound on Kjeldahl’s analysis gave enough ammonia to just neutralize $10$ cm$^{3}$ of 1 M $H_{2}SO_{4}$. The percentage of nitrogen in the compound is

Answer 1

$1$ M of $10$ ml $H_{2}SO_{4} = 1$ M of $20$ ml of $NH_{3}$
$1000$ ml of $1$ M ammonia contain $= 14$ g of nitrogen
$20$ ml of $1$ M ammonia contain $=\frac{14\times20}{1000}$g of nitrogen
$=\frac{14\times20}{1000} \times \frac{100}{0.5} =56.0\%$