Question

Concentrated sulphuric acid is a good drying agent. Can you tell why concentrated $H_{2}S{O}_4$ is not used to dry ammonia?

• A. Since $N{H}_3$ and $H_{2}S{O}_4$ are base, no reaction occurs.
• B. Since $N{H}_3$ and $H_{2}S{O}_4$ are acidic, no reaction occurs.
• C. Since $N{H}_3$ is a base and $H_{2}S{O}_4$ is an acid, together they will form a salt.
• D. None of the above

Answer 1

The correct option is C

Since $N{H}_3$ is a base and $H_{2}S{O}_4$ is an acid, together they will form a salt.

Since $N{H}_3$ is base and concentrated $H_{2}S{O}_4$ is an acid, the latter cannot dry the gas. Instead, the acid will react with ammonia to form white fumes of ({(N{H}_4)}_2S{O}_4\).

$2N{H}_3+Conc.H_{2}S{O}_4\to (N{H}_4{)}_{2}S{O}_4$