6g of the organic compound on heating with $\mathrm{NaOH}$ gave ${\mathrm{NH}}_3$which is neutralised by 200 mL of l $\mathrm{NHCl}.$ Percentage of nitrogen is :

Let X serve as a representation of the chemical compound.

$\mathrm{X}+\mathrm{NaOH}\cdots {\mathrm{NH}}_3+\mathrm{HCL}\cdots {\mathrm{NH}}_4\mathrm{Cl}$

The amount of generated ${\mathrm{NH}}_3$ is $200*1/1000$. Since the weight of nitrogen in an organic compound and the weight of nitrogen in ${\mathrm{NH}}_3$ are equal, the proportion of nitrogen in an organic compound equals $(2.8/6)*100$, or 46.67%.