JAMB - Chemistry (1979 - No. 17)

In the electrolysis of dilute sulphuric acid using platinum electrodes, the products obtained at the anode and cathode are:
Anode Cathode

Sulphur hydrogen

Hydrogen oxygen

Oxygen Hydrogen

Hydrogen sulphate ions

Sulphur oxygen

Dissociation of sulfuric acid,

\(H_2SO_4→2H^+_{(aq)}+SO^{−2}_{4(aq)}\)

Dissociation of water,

\(H_2O→H^+_{(aq)} + OH^−_{(aq)}\)

At Anode : \(4OH^−→2H_2O_{(l)} + O_{2(g)} + 4e_{−}\)

At Cathode : \(2H^+_{(aq)} + 2e^− → H_{2(g)}\)