Question

Impure ____________ is used as anode in the electrolytic refining of copper. ( zinc/copper)

Answer 1

Electrolytic refining

By using electricity, an impure metal taken as an anode can be refined. This technique is called electrolytic refining.

At the anode, the impure metal oxidises and forms its respective cations.

The chemical reaction at the anode:

Oxidation: $$\begin{gathered} \mathrm{Cu}\left(\mathrm{s}\right)\to {\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-} \\ \mathrm{impure} \end{gathered}$$

These cations pass into the solution and deposit at the cathode by gaining electrons.

$$\begin{gathered} {\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}\to \mathrm{Cu}\left(\mathrm{s}\right) \\ \mathrm{pure} \end{gathered}$$

During this process, the metal's salt solution is used as the electrolyte.

Thus, the impure copper anode can be refined be electrorefining

Hence, impure copper is used as an anode in the electrolytic refining of copper.