Give a balanced equation for preparation of HCl gas in the laboratory from sodium chloride.

In the laboratory preparation of HCl from sodium chloride, state why the following are preferred –

(i) Conc. H₂SO₄ as a reactant

(ii) Temp. below 200°C

(iii) Conc. H₂SO₄ as a drying agent.

Compare the density of HCl gas with air and state the solubility of HCl gas in water.

State why HCl gas forms a mist of droplets of HCl acid in moist air.