Alkali metals are obtained by the electrolysis of the molten salts and not by the electrolysis of their aqueous solutions. Give reason.

Explanation

The solution of alkali metal salts contains metal ions, `H^(o+)`, `overset(Θ)OH` and the anions. The discharge potaintal of the `H^(o+)` ion is lower than the metal cations and thus, on electrolysis of solutions of alkali metal salts, hydrogen is discharged at the cathode, rather than the metal. However, on electrolysis of the molten salt, the metal cation only present gets discharged at the cathode.