Question

During the electrolytic extraction of Aluminium, purified alumina is mixed with $N{a}_3$ $Al{F}_6$ and $Ca{F}_2$. Why?

• A. They increase the conductivity
• B. They increase the Melting point of the mix
• C. They decrease the conductivity
• D. They decrease the Melting Point of the mix

Answer 1

Answer: (A), (D)

The correct options are
A

They increase the conductivity

D

They decrease the Melting Point of the mix

In the metallurgy of Aluminium, purified alumina is mixed with $N{a}_3$$Al{F}_6$ and $Ca{F}_2$. Cryolite $\left(N{a}_{3}Al{F}_6\right)$ helps dissolve Alumina and lowers the melting point of this mix to about 1050 ${}^{0}C$. Alumina melts at about 2100 ${}^{0}C$. $Ca{F}_2$ is added to enhance the conductivity.