Question

You have been given an inorganic mixture with a knowledge that group II is absent but when $H_{2}S$ gas is passed into the mixture acidified with dilute $HCl$, yellowish turbidity appears due to presence of sulphur.

If true enter 1, else enter 0.

Answer 1

The statement given is true.

Inorganic mixture has no group II present but when $H_{2}S$ gas is passed into the mixture acidified with dilute HCl, yellow turbidity appears. It is due to the presence of some oxidising agents (acidic radicals like $N{O}_2^{-},N{O}_3^{-}$) which oxidises $H_{2}S$ to collodial sulphur (yellowish turbidity).

$H_{2}S+O\to H_{2}O+S$ (collodial yellowish turbidity)