Of the following,which cannot be obtained by electrolysis of the aqueous solution of their salts?

When $CuSO_4$ is electrolyzed using platinum electrodes,what happens?

Electrolysis of aqueous copper $(II)$ sulphate between $Pt$ electrodes gives '$X$' at anode and '$Y$' at cathode. $X$ and $Y$ are respectively

Which of the following is produced by the electrolysis of $NaCl$?

In the $Castner-Kellner$ cell for the production of sodium hydroxide,which of the following occurs?

The incorrect statement about the Castner-Kellner cell process is