Question

In the context of the Hall - Heroult process for the extraction of Al, which of the following statements is false?

• A. $CO$ and $C{O}_2$ are produced in this process
• B. $A{l}_2{O}_3$ is mixed with $Ca{F}_2$ which lowers the melting point of the mixture and brings conductivity
• C. $A{l}^{3+}$ is reduced at the cathode to $Al$
• D. $N{a}_{3}Al{F}_6$ serves as the electrolyte

Answer 1

The correct option is D $N{a}_{3}Al{F}_6$ serves as the electrolyte

In the Hall - Heroult process for the extraction of $Al$, the electrolyte used is a fused mixture of alumina (2-8%, synthetic cryolite $N{a}_{3}Al{F}_6$ (80-85%), $Al{F}_3$ (5-7%) and fluorspar, $Ca{F}_2$ (5-7%).