● The impure copper metal is made anode(positive).

● A thin strip of pure copper is made cathode(negative).

● The cathode and anode are immersed in the acidified copper sulphate solution and a battery is connected across them.

● The acidified Copper Sulphate solution is used as the electrolyte.
When current is passed through the acidified Copper Sulphate solution, the copper ion present in the solution starts depositing on the cathode. Same amount of Copper is dissolved into the solution from the anode.
In this way, the pure copper is deposited at the cathode. The cathode gets thicker and the anode gets thinner as time passes during electrolysis. The impurities are left in the solution as anode mud.