Question

Given below are the steps for the extraction of copper from its ore. Write the reaction involved.

Electrolytic refining

Answer 1

Electrolytic refining

• Electrolytic refining is a technique that is used for the extraction and purification of metals by using electrolytic cells.
• In this method, the impure metal is used as an anode and the pure metal has used as a cathode.
• Soluble salt from the same metal is used as an electrolyte.
• When an electric current is passed through the circuit, pure metal gets deposited at the cathode, and the impure metal gets dissolved from the anode, reducing the size of the anode.
• Impurities from the metal get collected below the anode and are known as anode mud.

Electrolytic refining of copper

• Electrolyte: Solution of acidified Copper sulphate.
• Anode: Impure copper; $\mathrm{Cu}\left(\mathrm{s}\right)\to {\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}$
• Cathode: Strip of pure copper: ${\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}\to \mathrm{Cu}\left(\mathrm{s}\right)$
• On passing electric current, pure copper is deposited on the cathode, and impurities is collected below anode known as anode mud.

Diagram of Electro refining of Copper.

Therefore, in purification of copper, electro refining is used.