2H2 → 4H+ + 4e- (Oxidation)
ii) By cathode, oxygen is subtle by a leaky carbon electrode. Electrons pass by the external circuit, therefore deliver electrical energy, (current at all times flows in direction opposite to direction of flow of electrons). Positive hydrogen ions exceed through electrolyte to cathode.
At cathode, reduction takes place.
4e- + O2 + 4H+ → 2 H2O (Reduction) ...(II)
The generally reaction is a impulsive oxidation - reduction reaction. Combine action at two electrodes is obtained by adding equations (I) and (II)
2H2 + O2 → 2H2O