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

Electrolytic Refining of Copper: Labelled Diagram

Diagram Description:
- The setup involves two electrodes immersed in an acidic copper sulfate (CuSO₄) solution.
- The anode is constructed from impure copper.
- The cathode is a thin strip of pure copper.
- The electrolyte used is an acidified copper sulfate solution (CuSO₄ mixed with dilute H₂SO₄).

Labeled Components:
- Anode: Impure copper rod
- Cathode: Thin strip of pure copper
- Electrolyte: Acidified CuSO₄ solution
- Power Supply: Connected positively to the anode and negatively to the cathode.

Process when Electric Current is Applied:
1. Copper atoms from the impure anode undergo oxidation, losing electrons and forming Cu²⁺ ions that enter the solution.
    Cu (s) → Cu²⁺ (aq) + 2e⁻
2. These Cu²⁺ ions migrate to the cathode, accept electrons, and are deposited as pure copper.
    Cu²⁺ (aq) + 2e⁻ → Cu (s)
3. Impurities such as gold and silver fall to the bottom below the anode, forming a layer known as anode mud.

Summary:
Upon passing an electric current, the impure copper at the anode dissolves, while pure copper is deposited onto the cathode, thereby refining the metal.