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 fluorite
• 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

Answer: (B), (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 (fluorite) and cryolite. Cryolite reduced the melting temperature of the mixture and also acts as a solvent.
Hence, option (b) and (c) are correct.