Question

Explain why it is preferable to use a number of graphite electrodes as anode instead of a single electrode, during the above electrolysis

Answer 1

• In the electrolytic reduction of alumina oxidation occurs at cathode, and reduction occurs at anode.
• The electrodes used in the reaction are made up of graphite (carbon), during the electrolysis, at the anode oxygen gas is liberated which reacts with the electrode to form carbon dioxide and carbon monoxide.
• This leads to the burning of the electrodes, and this is why instead of a single graphite electrode it is useful to use a number of electrodes.