(N/A) One of the simplest electrolytic cells consists of two copper strips dipping in an aqueous solution of copper sulphate $(CuSO_4)$.
Construction: It consists of two copper electrodes immersed in an aqueous solution of copper sulphate. One electrode acts as the anode and the other as the cathode.
Working: When a $DC$ voltage is applied to the two electrodes,$Cu^{2+}$ ions migrate to the cathode (negatively charged) and undergo reduction:
$Cu^{2+}_{(aq)} + 2e^{-} \rightarrow Cu_{(s)}$
Copper metal is deposited on the cathode.
At the anode,copper metal is oxidized into $Cu^{2+}$ ions:
$Cu_{(s)} \rightarrow Cu^{2+}_{(aq)} + 2e^{-}$
Thus,copper is dissolved (oxidized) at the anode.
Overall reaction: $Cu_{(s)} (\text{anode}) \rightarrow Cu_{(s)} (\text{cathode})$ (Impure $\rightarrow$ Pure).
Uses: This process is the basis for the electrolytic refining of copper,where impure copper is converted into high-purity copper. The impure copper is used as the anode,which dissolves upon passing current,and pure copper is deposited at the cathode.