Question

With respect to the electrolysis of copper (II) sulphate solution using copper electrodes, which statement is correct?

Options

• Copper metal is deposited at the negative electrode.

• Oxygen gas is produced at the positive electrode.

• The positive electrode increases in mass.

• The negative electrode decreases in mass.

Answer 1

Copper metal is deposited at the negative electrode.

Explanation:

With copper electrodes Cu²⁺ is reduced at the cathode \[\ce{(Cu2+ + 2e− → Cu)}\] and deposits as metal, while the copper anode is oxidized to Cu²⁺ and dissolves (so the anode loses mass); oxygen at the positive electrode occurs only if inert electrodes are used.