Where, $\mathrm{p}_{2}=$ pressure of $\mathrm{N}_{2}$ at $\mathrm{STP}=760\, \mathrm{mm}$

$\mathrm{T}_{2}=$ Temperature of $\mathrm{N}_{2}$ at $\mathrm{STP}=273\, \mathrm{K}$

$V_{2}=?$

Volume of $\mathrm{N}_{2}$ at $\mathrm{STP}$ (by Gas equation)

$\left(\frac{\rho-\rho_{1}}{t+273}\right) V_{1} \times \frac{273}{160}=V_{2}$

Where $\mathrm{p}_{1}=\rho-\rho_{1}$

$\rho=715\, \mathrm{mm}$ (pressure at which $\mathrm{N}_{2}$ collected)

$\rho_{1}=$ aqueous tension of water $=15\, \mathrm{mm}$

$T_{1}=t+273=300\, k$

$\mathrm{V}_{1}=55\, \mathrm{mL}=$ volume of moist nitrogen in nitrometer $\therefore V_{2}=\frac{(715-15) \times 55}{300} \times \frac{273}{760}=40.098\, \mathrm{mL}$

$\%$ of nitrogen in given compound

$=\frac{28}{22400} \times \frac{V_{2}}{W} \times 100$

$=\frac{2}{22400} \times \frac{46.09}{0.35} \times 100$

$=16.45 \%$