In the extraction of which of the following,a complex ion is formed?

Suggest a condition under which magnesium could reduce alumina. The two equations are:
$(a)$ $\frac{4}{3} Al + O_2 \rightarrow \frac{2}{3} Al_2O_3$
$(b)$ $2 Mg + O_2 \rightarrow 2 MgO$

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

In the commercial electrochemical process for aluminium extraction,the electrolyte used is:

The term $Smelting$ is used for a process in which ......

Which of the following is electrolyzed for the extraction of aluminum?