Spelter is

Considering the Ellingham diagram,which of the following metals can be used to reduce alumina $(Al_2O_3)$?

Name the metal $M$ which is extracted on the basis of following reactions:
$4M + 8CN^{-} + 2H_2O + O_2 \rightarrow 4[M(CN)_2]^{-} + 4OH^{-}$
$2[M(CN)_2]^{-} + Zn \rightarrow [Zn(CN)_4]^{2-} + 2M$

Explain the role of thermodynamics in the extraction of elements. Or,explain how thermodynamics is helpful in the selection of a reducing agent for metallurgical operations.

In the equation,$4M + 8CN^{-} + 2H_2O + O_2 \to 4[M(CN)_2]^- + 4OH^{-}$,the metal $M$ is

For the electrolytic production of aluminium,$(i)$ the cathode and $(ii)$ the anode are made of