JEE Main20238 Apr 2023Evening ShiftChemistryGeneral Principles and Processes of Isolation of MetalsActual
In Hall-Heroult process, the following is used for reducing Al 2 O 3 :-
Options
- AMagnesium
- BNa 3 AlF 6
- CGraphite
- DCaF 2
Correct answer
C. Graphite
Step-by-step solution
The process of extracting Al metal by electrolysis of a mixture of purified Al 2 O 3 and   Na 3 AlF 6 is known as Hall and Heroult process. Graphite is used as anode which is useful in the reduction of alumina oxide to the Al   metal. The graphite electrode reacts with the oxygen released at cathode to form carbon dioxide and carbon monoxide. Therefore, the role of graphite as an anode in the extraction of Al is to check the formation of oxygen. In other words, we can say its role is to prevent the oxidat