(N/A) Procedure: $A$ known mass of an organic compound is heated with fuming nitric acid in the presence of silver nitrate contained in a hard glass tube known as a Carius tube in a furnace.
Principle: Carbon and hydrogen present in the organic compound are oxidized to carbon dioxide and water. The halogen present forms the corresponding silver halide $(AgX)$. It is filtered,dried,and weighed.
$AgNO_{3} + X \xrightarrow{HNO_{3}} \Delta AgX_{(s)}$
Mass of organic compound $= m \ g$
$1 \ mol$ of $AgX$ contains $1 \ mol$ of $X$.
Therefore,the mass of halogen in $m_{1} \ g$ of $AgX$ is,
Mass of halogen $= \frac{\text{atomic mass of } X \times m_{1}}{\text{molecular mass of } AgX}$
Therefore,% of halogen $= \frac{(\text{atomic mass of } X)(m_{1})(100)}{(\text{molecular mass of } AgX)(m)}$