In the electrolytic extraction of aluminum,molten cryolite $(Na_3AlF_6)$ is used to:

Observe the following statements:
Statement-$I$: The choice of reducing agent for the reduction of an oxide ore can be predicted by using Ellingham diagram,a plot of $\Delta G^{\ominus}$ vs $T$.
Statement-$II$: According to Ellingham diagram,metal oxide with higher $\Delta G^{\ominus}$ is more stable than the oxide with lower $\Delta G^{\ominus}$.

In the extraction of iron using a blast furnace,to remove the impurity $(X)$,chemical $(Y)$ is added to the ore. $X$ and $Y$ are respectively

Who studied the plots of $\Delta G$ versus $T$?

Explain electrometallurgy in detail.

During the extraction of gold,the following reactions take place: $4Au + 8CN^{-} + 2H_2O + O_2 \longrightarrow 4[Au(CN)_2]^{-} + 4OH^{-}$ and $2[Au(CN)_2]^{-} + Zn \longrightarrow [Zn(CN)_4]^{2-} + 2Au$. $X$ and $Y$ are respectively: