In the Hall-Heroult process, aluminium is formed at the cathode. The cathode is made out of: platinum, pure aluminium, carbon, copper
copper
platinum
pure aluminium
carbon
Solution:
The hall-heroult process is used for smelting of aluminium. In the Hall-Heroult process, the cathode is made of carbon. Also, here anode is also made up of carbon. Hence, the correct option is carbon.