Question

Which method is used to find halogen in organic compound?

• A. Duma's method
• B. Leibig's method
• C. Kjeldahl method
• D. Carius method

Answer 1

Answer: (D)

Carius method is used to find halogen in an organic compound. In this method, the weighed amount of organic compound is heated in a sealed tube with fuming $HN{O}_3$ in the presence of $AgN{O}_3$. As a result, halogen present in organic compound is converted into $AgX$ which is weighed. The percentage of halogens can be calculated with the help of direct formula as :
$\%$ of chlorine $=\frac{35.5}{143.5}\times \frac{\text{ mass of }AgCl\times 100}{\text{ mass of compound }}$
$\%$ of bromine $=\frac{80}{188}\times \frac{\text{ mass of }AgBr\times 100}{\text{ mass of compound }}$
$\%$ of iodine $=\frac{127}{235}\times \frac{\text{ mass of AgI }\times 100}{\text{ mass of compound }}$