0.28 g of an organic compound in Dumas method liberated 22.4 ml of nitrogen at STP. The percentage of nitrogen in the compound is

The Dumas method of molecular weight measurement was employed to determine the molecular weight of an unknown material. The Dumas method can be used to calculate the molecular weights of volatile organic compounds that are liquids at room temperature.

Dumas method:       $\% \mathrm{N} =\frac{\mathrm{volume} {\mathrm{ofN}}_2 \mathrm{at} \mathrm{STP}}{8\times \mathrm{weight} \mathrm{of} \mathrm{organic} \mathrm{compound}}=\frac{22.4}{8\times 0.28}=10$

Hence, correct option is: (A) 10