Question

Electrolytic reduction of alumina to aluminium by Hall-Heroult's process is carried out _____________.

• A. in the presence of sodium chloride
• B. in the presence of flourite
• C. in the presence of cryolite which forms a melt with lower melting temperature
• D. in the presence of cryolite which forms a melt with higher melting temperature

Answer 1

The correct option is C in the presence of cryolite which forms a melt with lower melting temperature

In the extraction of aluminium by electrolytic process, alumina $A{l}_2{O}_3$ is used along with fluorspar and cryolite. Cryolite reduces the melting temperature of the mixture and also acts as a solvent.