Question

The constituents of the electrolyte for the extraction of aluminium is ____________.

• A. 40 parts cryolite + 40 parts fluorspar + 20 parts pure $A{l}_2{O}_3$
• B. 60 parts cryolite + 30 parts fluorspar + 10 parts pure $A{l}_2{O}_3$
• C. 30 parts cryolite + 30 parts fluorspar + 40 parts pure $A{l}_2{O}_3$
• D. 60 parts cryolite + 20 parts fluorspar + 20 parts pure $A{l}_2{O}_3$

Answer 1

The correct option is D 60 parts cryolite + 20 parts fluorspar + 20 parts pure $A{l}_2{O}_3$

Pure alumina melts at about ${2000}^{o}C$ and is a bad conductor of electricity. If fused cryoliteand fluorspar is added, the mixture melts at ${900}^{o}C$ and $A{l}_2{O}_3$ becomes a good conductorof electricity.
Electrolyte: 60 parts cryolite + 20 parts fluorspar + 20 parts pure $A{l}_2{O}_3$