Cold concentrated ${\mathrm{HNO}}_3$ will completely dissolve:
$\left(\mathrm{i}\right)$ $\mathrm{Pb}$
$\left(\mathrm{ii}\right)$ ${\mathrm{Pb}}_3{\mathrm{O}}_4$
$\left(\mathrm{iii}\right)$ $\mathrm{Fe}$
$\left(\mathrm{iv}\right)$ $\mathrm{Sn}$
$\left(\mathrm{v}\right)$ $\mathrm{Mg}$
$\left(\mathrm{vi}\right)$ $\mathrm{MgO}$
$\left(\mathrm{vii}\right)$$\mathrm{Hg}$
$\left(\mathrm{viii}\right)$ $\mathrm{Au}$
$\left(\mathrm{ix}\right)$ $\mathrm{Ag}$
$\left(\mathrm{x}\right)$ $\mathrm{Pt}$

In the process of extraction of gold:

$\mathrm{Roasted} \mathrm{gold} \mathrm{ore}+{\mathrm{CN}}^{-}+{\mathrm{H}}_2\mathrm{O}\stackrel{{\mathrm{O}}_2}{\to }\mathrm{ }\left[\mathrm{X}\right]\mathrm{ }+{\mathrm{OH}}^{-}$
$\left[\mathrm{X}\right]+\mathrm{Zn}⟶\left[\mathrm{Y}\right]+\mathrm{Au}$
Identify the complexes [$\mathrm{X}$] and [$\mathrm{Y}$].

Extraction of zinc from zinc blende is achieved by _____.