In Duma’s method of estimation of nitrogen, 0.1840g of an organic compound gave 30mL of nitrogen collected at 287K and 758 mm of Hg pressure. The percentage composition of nitrogen in the compound is (round off to the Nearest Integer)

Given data: 

In estimation of nitrogen, 0.1840g of an organic compound gave 30mL of nitrogen collected at 287K and 758mm of Hg pressure.

To find, the percentage of nitrogen in the compound.

Explanation;

Let us the look at the equation

Mass of the organic substance is 0.3 g
 Here, Volume of the Nitrogen which is collected = 50 mL
 Temperature stated as T1 = 300 K

V pressure of water is 15 mm
 Now the actual pressure in dry nitrogen is 715−15=700 mm
 In STP, P_2​=760 mm and T_2​=273 K then V2​=?
 T_1​P_1​V₁​​=T₂​P_2​V₂​​

300$\times$700×50​=273$\times$760×V2

or

$\begin{array}{r}\text{ Mass }\mathrm{\%}\text{ of }{N}_2=\frac{\text{ mass of }N\times 100}{\text{ total mass }}\\ =\frac{34.888\times {10}^{-3}\times 100}{0.184}\\ \end{array}$