Formation of metallic copper from the sulphide ore in the commercial thermo-metallurgical process essentially involves which one of the following reactions as the major reaction?

Aluminium is prepared in large quantities by

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 $\Delta G^{\ominus}$.

From which of the following is silver obtained by the reaction with $Na[Ag(CN)_2]$?

Copper is the most noble of the first row transition metals and occurs in small deposits in several countries. Ores of copper include chalcanthite $(CuSO_4 \cdot 5H_2O)$,atacamite $(Cu_2Cl(OH)_3)$,cuprite $(Cu_2O)$,copper glance $(Cu_2S)$ and malachite $(Cu_2(OH)_2CO_3)$. However,$80\%$ of the world copper production comes from the ore of chalcopyrite $(CuFeS_2)$. The extraction of copper from chalcopyrite involves partial roasting,removal of iron and self-reduction. $1.$ Partial roasting of chalcopyrite produces: $(A)$ $Cu_2S$ and $FeO$ $(B)$ $Cu_2O$ and $FeO$ $(C)$ $CuS$ and $Fe_2O_3$ $(D)$ $Cu_2O$ and $Fe_2O_3$. $2.$ Iron is removed from chalcopyrite as: $(A)$ $FeO$ $(B)$ $FeS$ $(C)$ $Fe_2O_3$ $(D)$ $FeSiO_3$. $3.$ In self-reduction,the reducing species is: $(A)$ $S$ $(B)$ $O^{2-}$ $(C)$ $S^{2-}$ $(D)$ $SO_2$. Give the answer for questions $1, 2$ and $3$.

Explain the reduction process involved in the extraction of zinc.