In which process does a chemical change occur when an electric current is passed through it?

Electrolysis of molten anhydrous calcium chloride produces

Give the electrolytic reaction of $CuSO_4$ solution using $Cu$ electrodes.

Write the reactions for the following:
$A$. Electrolytic reaction of concentrated and dilute solution of $H_2SO_4$.
$B$. Oxidation reaction of $SO_4^{2-}$.

The cell used for the electrolysis of fused $NaCl$ is

During the electrolysis of fused $NaCl$,the product obtained at anode is