Kjeldahl's method was used for the estimation of nitrogen in an organic compound. The ammonia evolved from 0.55 g of the compound neutralised 12.5 mL of $1 \mathrm{M} {\mathrm{H}}_2{\mathrm{SO}}_4$ solution. The percentage of nitrogen in the compound is__________.(Nearest integer)

Meq of H₂SO₄ used by NH₃ = 12.5 × 1 × 2 = 25
% of N in the compound = $\frac{25\times {10}^{-3}\times 14\times 100}{0.55}=63.6$
or
Meq. of H₂SO₄ = Meq. of NH₃
12. 5 × 1 × 2 = 25 meq. of NH₃
= 25 millimoles of NH₃
So Millimoles of 'N' = 25
Moles of 'N' = 25 × 10^–3
wt. of N = 14 × 25×10^–3
$\begin{array}{l}\mathrm{\%}\mathrm{N}=\frac{14\times 25\times {10}^{-3}}{0.55}\times 100\\ =63.66\\ \approx 64\mathrm{\%}\end{array}$