Question

For the electrorefining of copper:

1. What is the cathode made up of ?
2. Write the reaction that takes place at the anode.

Answer 1

The chemical process of purification of metal by electrolytic reduction is known as electrorefining. The anode is impure metal whereas the cathode is of pure metal.

For the electrorefining of copper:

1. The cathode is made up of pure copper metal.
2. The anode is made up of impure copper metal where oxidation of copper occurs by loss of electrons.

Reaction at anode: $$\begin{gathered} \mathrm{Cu}\left(\mathrm{s}\right)\to {\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-} \\ \mathrm{copper}\mathrm{metal}\mathrm{copper}\mathrm{ion} \end{gathered}$$