• # question_answer In Dumas' method of estimation of nitrogen 0.35 g of an organic compound gave 55 mL of nitrogen collected at 300 K temperature and 715 mm pressure. The percentage composition of nitrogen in the compound would be: (Aqueous tension at 300 K =15 mm) A)  14.45B)  15.45C)  16.45D)  17.45

${{P}_{{{N}_{2}}}}=715-15=700\,mm$ $V=55\,mL$ $\therefore$      $PV=\frac{w}{M}RT$ $\frac{700}{760}\times \frac{55}{1000}=\frac{{{w}_{{{N}_{2}}}}}{28}\times 0.0821\times 300$ ${{w}_{{{N}_{2}}}}=0.058\,g$ $\therefore$% ${{N}_{2}}=\frac{0.058}{0.35}\times 100=16.45$s