Question

In Carius method for estimation of halogens, 180 mg of an organic compound produced 143.5 mg of AgCl. The percentage composition of chlorine in the compound is ___________%. [Given: Molar mass in g mol\(^{-1}\) of Ag = 108, Cl = 35.5]

Hint:

To calculate the percentage composition of an element, divide the mass of the element by the total mass of the compound and multiply by 100.

Answer 1

Correct Answer: 20

The moles of Cl in AgCl are: \[ n_{\text{Cl}} = n_{\text{AgCl}} = \frac{143.5 \times 10^{-3}}{143.5} = 10^{-3} \] The percentage composition of Cl is: \[ \% \text{Cl} = \frac{10^{-3} \times 35.5}{180 \times 10^{-3}} \times 100 = 19.72 \% \] Thus, the percentage composition of chlorine is approximately 20%.