Which one of the following is not true in electrolytic refining ?

The cathode is made up of impure metal, Cathode is of impure metal and the anode is of pure metal Both electrodes must be of pure metal is not true in electrolytic refining.

The impure metal is produced to serve as an anode in the electrolytic refining process. The cathode is a strip of the same metal in its purest form. They are placed in an appropriate electrolytic bath that contains a soluble metal salt. Less basic metals end up in the anode mud while more basic metals stay in the solution.

When copper is refined electrolytically, strips of impure copper are used as the anode and a solution of acidified copper sulphate is used as the cathode. Anode mud is made of impurities from the blister copper deposit.

Hence, options A, C and D are correct