Extraction of copper by smelting uses silica as an additive to remove

During the cyanide process,the silver complex ion formed is......

During the extraction of sodium metal by electrolysis,a mixture of $40\% \ NaCl$ and $60\% \ CaCl_2$ is used because...

Which one of the following metals is extracted by thermal reduction process?

The metal extracted by the electrolysis of its fused salt is

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: