Answer:
Carbon anodes need to be replaced periodically to avoid oxidation. During the Electrolysis of the Alumina, Oxygen is deposited at the anode. The oxygen reacts with the carbon anodes causing the formation of carbon dioxide. Anode is made up of the graphite (or Carbon), thus carbon reacts with the Oxygen and forms its oxide. As a result of this Oxidation, we need to replace the anode from time to time
