Aluminum is exteracted from alumine `AI_(2)O_(3)` by electrolysis of a molten mixture of :

Options

A. `Al_(2)O_(3) + HF + NaAlF_(4)`
B. `Al_(2)O_(3) + CaF_(2) + NaAlF_(4)`
C. `Al_(2)O_(3) + Na_(3)AlF_(6) + CaF_(2)`
D. `Al_(2)O_(3) + KF + Na_(3)AlF_(6)`

Answer

C

Explanation

Alumina, `Al_(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 `(CaF_(2))` and cryolite `(Na_(3)AlF_(6))`, which lower its melting point and make it more conducting. Mainly `CaF_(2)` and `Na_(3)AlF_(6)` are mixed with `Al_(2)O_(3)` for converting `Al_(2)O_(3)` in molten state.