During the electrolysis of acidified water, where would oxygen and hydrogen gas be liberated?
Therefore, the reaction which occurs at cathode is:
2H3O+(aq)+2e−→H2(g)+2H2O(l)
Though the ion which moves towards anode is SO2−4, the actual reaction which occurs at anode is:
2H2O(l)→O2(g)+4H+(aq)+4e−
This is because water has a high tendency to get oxidised than SO2−4.
Hence, oxygen gas gets liberated at anode and hydrogen gas gets liberated at cathode.