Question

Considering Ellingham diagram, which of the following metals can be used to reduce alumina?

Answer 1

Considering Ellingham diagram. $Mg$ metal can be used to reduced alumina.
The negative free energy change for the formation of $MgO$ from $Mg$ is greater than that for the formation of $A{l}_2{O}_3$ from $Al$

Hence, $Mg$ has greater tendency to undergo oxidation than $Al$. Hence, $Mg$ is oxidised and $A{l}_2{O}_3$ is reduced to $Al$.

Note: More negative the value of $\Delta G$, the greater is the tendency, of the element to combine with Oxygen.