Give balanced equations for the electrode reactions involved in the following conversions at the respective electrodes:

1. Aluminium oxide → Oxygen gas ← Copper [II] Sulphate
2. Copper metal → Copper ions → Copper metal
3. Lead [II] chloride → Chlorine gas ← Hydrochloric acid
4. Hydroxyl ions ← Acidified water → Oxygen gas
5. Potassium bromide → Bromine gas ← Lead bromide

Select the correct answer from the list in bracket:

1. The cation discharged at the cathode most readily.
   [Fe²⁺, Cu²⁺, Pb²⁺, H¹⁺]
2. The anion discharged at the anode with most difficulty.
   [SO₄^2-, Br^1-, NO₃^1-,OH^1-]
3. The metallic electrode which does not take part in an electrolytic reaction.
   [Cu, Ag, Fe, Ni]
4. The ion/s which is/are discharged during electrolysis of aq. CuSO₄ using Cu electrode.
   [Cu²⁺, SO₄^2-, H¹⁺, OH^1-]
5. A covalent compound which in aqueous state conducts electricity.
   [CCl₄, CS₂, NH₃, C₂H₄]

Give reason for the following :

Lead bromide undergoes electrolytic dissociation in the molten state but is a non-electrolyte in the solid state.

Give reason for the following :

The blue colour of aq. copper sulphate does not change when it is electrolysed using copper electrodes.