General Principles and processes of Isolation of Elements
medium

Aluminium is extracted from alumina $(Al_2O_3)$ by electrolysis of a molten mixture of

A

$Al_2O_3 + HF + NaAlF_4$

B

$Al_2O_3 + CaF_2 + NaAlF_4$

C

$Al_2O_3 + Na_3AlF_6 + CaF_2$

D

$Al_2O_3 + KF + Na_3AlF_6$

(AIPMT-2012)

Solution

Alumina, $A l_{2} O_{3}$ is a bad conductor of electricity and has very high melting point, so before subjecting to electrolysis, it is mixed with fluorspar $\left(C a F_{2}\right)$ and cryolite $\left(N a_{3} A l F_{6}\right),$ which lower its melting point and make it more conducting. Mainly $C a F_{2}$ and $N a_{3} A l F_{6}$ mixed with $A l_{2} O_{3}$ for converting in molten state.

Standard 12
Chemistry

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.