In the extraction of copper from copper glance,blister copper is formed by the evolution of gas $\underline{X}$. The shape of the molecule of $\underline{X}$ is

Statement $I :$ Leaching of gold with cyanide ion in absence of air $/$ $O_2$ leads to cyano complex of $Au(III)$.
Statement $II :$ Zinc is oxidized during the displacement reaction carried out for gold extraction.
In the light of the above statements,choose the correct answer from the options given below.

$Pb$ and $Sn$ are extracted from their chief ores by:

Explain the reduction process involved in the extraction of zinc.

What is the purpose of adding $Na_3AlF_6$ to $Al_2O_3$ during electrolysis?

Which one of the following is used in the extraction of aluminium by the electrolytic process?