Question

(i) Write the balanced chemical equation to prepare ammonia gas in the laboratory by using an alkali.
(ii) State why concentrated sulphuric acid is not used for drying ammonia gas.
(iii) Why is ammonia gas not collected over water?

Answer 1

(i) $2N{H}_{4}Cl+Ca{\left(OH\right)}_2\to Ca{Cl}_2+2H_{2}O+2N{H}_3$

Here calcium hydroxide is the alkali.

(ii) Ammonia being basic in nature reacts with concentrated sulphuric acid and forms ammonium sulphate as follows:

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

(iii) Ammonia gas is soluble in water and therefore is not collected over water.