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

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.

Regards

Team

Topperlearning