Aqueous solution of ‘X’ is electrolyzed using inert electrodes. Hydrogen is liberated at cathode and oxygen is liberated at anode. ‘X’ is

At cathode, discharge potential of H2O is greater than that of K+∴ 2H2O+2e-→H2+2OH-At anode, discharge potential of H2O is greater than that of SO4−2∴ 2H2O → 4H++4e-+O2