Tue February 15, 2011 By: Srishti Aggarwal

Why so we need to replace carbon rods in electrolytic reduction of Al2O3(alumina) periodically?

Expert Reply
Fri February 18, 2011
Dear Student
During the process, the electrochemical reaction causes liquid aluminium metal to be deposited at the cathode as a precipitate, while the oxygen from the alumina combines with carbon from the anode to produce carbon dioxide, CO2.
The oxidation of the carbon anode reduces the required voltage across each cell. This is why we need to replace them with new ones.
We hope that clarifies your query.
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