A solution of sodium sulphate was electrolyzed using some inert electrode. The products at the electrodes are:
Since the reduction potential of H2O is greater than reduction potential of Na⊕soH2O undergoes reduction to give
H2(g) at cathode.
H2O+e−→⊖OH+12H2(g)
Similarly, the oxidation potential of H2O is greater than the oxidation potential of SO2−4 ion. So, H2O undergoes oxidation to give O2(g) at anode.
H2O→2H⊕+2e−+12O2(g)