$0.2 \ g$ of an organic compound was subjected to estimation of nitrogen by Dumas method in which volume of $N_2$ evolved (at $STP$) was found to be $22.400 \ mL$. The percentage of nitrogen in the compound is $.......$. [nearest integer] (Given: Molar mass of $N_2$ is $28 \ g \ mol^{-1}$. Molar volume of $N_2$ at $STP$ : $22.4 \ L \ mol^{-1}$ )

What is the formula for calculating the percentage of nitrogen in the Dumas method?

On complete combustion,$0.246 \ g$ of an organic compound gave $0.198 \ g$ of carbon dioxide and $0.1014 \ g$ of water. Determine the percentage composition of carbon and hydrogen in the compound.

Sodium fusion extract of an organic compound $(Y)$ with $CHCl_3$ and chlorine water gives a violet color to the $CHCl_3$ layer. $0.15 \ g$ of $(Y)$ gave $0.12 \ g$ of the silver halide precipitate in the Carius method. The percentage of halogen in the compound $(Y)$ is . . . . . . . (Nearest integer). (Given: molar mass $g \ mol^{-1} C : 12, H : 1, Cl : 35.5, Br : 80, I : 127$)

Discuss the Dumas method and its principles for the estimation of $N$ present in an organic compound.

$6.46 \ g$ of $BaSO_4$ is obtained from $4.81 \ g$ of a compound in the estimation of sulphur by the Carius method. Calculate the percentage of sulphur in the compound. (Atomic masses: $Ba = 137, S = 32, O = 16$)