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

Copper can be extracted by hydrometallurgy but not zinc as per the below-given reason:  

 The Eo of zinc ( Zn2+/Zn = - 0.76V) is lower than that of copper (Cu2+/Cu = 0.34V).  this means that zinc is a stronger reducing agent and can displace copper from a solution of Cu2+ ions.

 Zn (s) + Cu2+ (aq) → Zn2+ + Cu (s)

In order to displace zinc by hydrometallurgy, we need stronger reducing agent like K ( EoK+/K = - 2.93V)

 2K (s) + 2H2O (l) → 2KOH (aq) + H2 (g)

As a result, these metals cannot be used in hydrometallurgy to extract zinc. Hence, copper can be extracted by hydrometallurgy but not zinc.