Assertion: In Hall-Heroult process aluminium is extracted by the electrolytic reduction of alumina dissolved in molten cryolite or fluorspar.
Reason: The cryolite ore fluorspar lower the melting point of melt an dmake it more conducting

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If assertion is false but reason is true.

Answer

B

Explanation

Assertion: True but is reason is that aluminium cannot be extracted `(i)` from `A1_(2)O_(3)` by its reduction with carbon at high temperatures (there is possibility of formation of `A1C_(3) (ii)` by electroysis of their salts solution as aluminium liberated at cathode will immediately react with `H_(2)O` forming `A1(Oh)_(3)`.
Reason: The statement is correct as cryolite or fluorspar lowers the melting point of alumina as impurity. Both being ionic compounds ionize to give ions and increase the electric conductivity.