In the process of leaching of gold by cyanide,what are the complexes $X$ and $Y$ respectively?
$4Au(s) + 8CN^-(aq) + 2H_2O(aq) + O_2(g) \to 4[Au(CN)_2]^-(aq) + 4OH^-(aq)$
$2[Au(CN)_2]^-(aq) + Zn(s) \to [Zn(CN)_4]^{2-}(aq) + 2Au(s)$
$X$ and $Y$ are:

The correct statement regarding the given Ellingham diagram is

Blister copper is.......

Given are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Magnesium can reduce $Al_{2}O_{3}$ at a temperature below $1350^{\circ} C$,while above $1350^{\circ} C$ aluminium can reduce $MgO$.
Reason $R$: The melting and boiling points of magnesium are lower than those of aluminium.
In light of the above statements,choose the most appropriate answer from the options given below:

Among the following groups of oxides,the group containing oxides that cannot be reduced by carbon to give the respective metals is

Blister $Cu$ contains approximately ....... $\%$ $Cu$.