Question

Draw a labelled diagram to show electrolytic refining of copper. State what happens when electric current is passed through the electrolyte taken in this case.

Answer 1

 

Labelled Diagram: Electrolytic Refining of Copper

Diagram Description:
- Two electrodes are dipped into an acidic copper sulphate (CuSO₄) solution.
- The anode is made of impure copper.
- The cathode is made of a thin strip of pure copper.
- Electrolyte: Acidified copper sulphate solution (CuSO₄ + dilute H₂SO₄).

Labelled Parts:
- Anode (Impure copper rod)
- Cathode (Thin strip of pure copper)
- Electrolyte (Acidified CuSO₄ solution)
- Power supply (positive to anode, negative to cathode)

What happens when electric current is passed:
1. Copper atoms from the impure copper anode lose electrons and go into the solution as Cu²⁺ ions.
    Cu (s) → Cu²⁺ (aq) + 2e⁻
2. These Cu²⁺ ions move towards the cathode, gain electrons, and get deposited as pure copper.
    Cu²⁺ (aq) + 2e⁻ → Cu (s)
3. Impurities like gold and silver settle down below the anode as anode mud.

Conclusion:
On passing electric current, pure copper gets deposited on the cathode, and impure copper dissolves from the anode, refining the metal.