Copper can be extracted by hydrometallurgy but not zinc. Explain.

(N/A) The reduction potentials of $Zn$ and $Fe$ are lower than that of $Cu$. In hydrometallurgy,metals like $Fe$ can be used to displace $Cu$ from its aqueous solution.
$Fe_{(s)} + Cu_{(aq)}^{2+} \to Fe_{(aq)}^{2+} + Cu_{(s)}$
However,to displace $Zn$ from its solution,more reactive metals (i.e.,metals having lower reduction potentials than $Zn$) such as $Mg, Ca, K,$ etc.,are required.
These highly reactive metals react vigorously with water to evolve $H_2$ gas instead of displacing the metal.
$2K_{(s)} + 2H_2O_{(l)} \to 2KOH_{(aq)} + H_{2(g)}$
As a result,these metals cannot be used in hydrometallurgy to extract $Zn$. Hence,$Cu$ can be extracted by hydrometallurgy but not $Zn$.