Question

With respect to the Hall Heroult process, justify the following:

Along with cryolite and alumina, another substance is added to the electrolyte mixture. Name the substance and give one reason for the addition.

Answer 1

Fluorspar (CaF₂) is the additional substance added because it acts as a solvent and increases the fluidity of the electrolytic bath so the molten aluminium can settle at the bottom more easily.