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

Which of the following statements is not correct?
$1$. Reduction of alumina to give aluminium by magnesium is thermodynamically feasible.
$2$. The point of intersection of $Al_2O_3$ and $MgO$ curves in Ellingham diagram is below $1665 \ K$.
$3$. Use of magnesium as reducing agent in metallurgy of aluminium is economical.
$4$. Ellingham diagram represents the graphical plot of Gibbs energy vs temperature for the formation of the oxides of common metals and reducing agents.

Carbon and $CO$ gas are used to reduce which of the following pairs of metal oxides for the extraction of metals?

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:

Thermite is a mixture of $X$ parts of ferric oxide and $Y$ parts of aluminium powder. $X, Y$ respectively are

During the electrolytic reduction of alumina,two auxiliary electrolytes $X$ and $Y$ are added to increase the electrical conductance and lower the melting point of the mixture. $X$ and $Y$ are: