Question

What is the role of graphite rod in in the electrolytic refuction of alumina?

Answer 1

#BAL

In the electrometallurgy of aluminium, a fused mixture of purified alumina (Al2O3), cryolite (Na3AlF6) and fluorspar (CaF2) is electrolysed. In this electrolysis, graphite is used as the anode and graphite-lined iron is used as the cathode. During the electrolysis, Al is liberated at the cathode, while CO and CO2 are liberated at the anode.If a metal is used instead of graphite as the anode, then O2 will be liberated. This will not only oxidise the metal of the electrode, but also convert some of the Al liberated at the cathode back into Al2O3. Hence, graphite is used for preventing the formation of O2 at the anode. Moreover, graphite is cheaper than other metals

Answer 2

Answer:

• Graphite rod is used as an anode and graphite line iron as cathode during the electrolysis of alumina. ... Thus the role of graphite in electrometallurgy of aluminium is to prevent the liberation of oxygen so that the aluminium is not oxidized by oxygen.