Question

Explain Elesctrolysis of HCl in simple way

Answer 1

The electrode reactions and products of the electrolysis of dil. hydrochloric acid are illustrated by the theory diagram above

The electrode half-equations for the electrolysis of dilute hydrochloric acid HCl(aq)

(a) The negative cathode electrode reaction for the electrolysis of hydrochloric solution

The positive hydrogen ions H+ (from hydrochloric acid) are attracted to the negative cathode electrode, and are reduced by electron gain to form hydrogen gas at the negative electrode.

2H+(aq) + 2e– ==> H2(g)

positive ion reduction by electron gain

or 2H3O+(aq) + 2e– ==> H2(g) + 2H2O(l)

All acids give hydrogen at the negative cathode.

 

(b) The positive anode electrode reaction for the electrolysis of hydrochloric solution

The (+) anode attracts both the OH– (from water) and Cl– ions (from hydrochloric acid). Only the chloride ion is discharged in appreciable quantities.

Chloride ions are oxidised by electron loss to form chlorine gas at the positive electrode.

2Cl–(aq) – 2e– ==> Cl2(g)

 or  2Cl–(aq) ==> Cl2(g) + 2e– 

negative ion oxidation by electron loss