Mention the reaction conditions and give balanced equations to obtain
(i) Cl2 gas from HCl gas.
(ii) Cl2 gas from HCl acid.
(iii) HCl gas from common salt.
(i) Decomposition of HCl gas at temperatures above 500o C gives chlorine and hydrogen gas.
2HCl(g) ⇌ H2(g) + Cl2(g)
(ii) When concentrated HCl acid reacts with strong oxidising agents, Cl2 is liberated.
MnO2 + 4HCl → MnCl2 (aq) + 2H2O + Cl2↑
(iii) Sodium chloride (common salt) and concentrated sulphuric acid react to produce HCl gas.
The reaction takes place as follows:
NaCl(s) + H2SO4(aq) → NaHSO4(s) + HCl(g)
Sodium chloride Sulphuric acid Sodium hydrogen Hydrogen chloride