Question

Which method would you suggest for the separation of the metal in the following mixture?

Zinc and iron

Give reasons for your choice.

Answer 1

For the separation of zinc and iron, the suitable method is Hydrometallurgy (selective leaching).

Reason:

1. Zinc can be selectively dissolved in dilute sulphuric acid to form ZnSO₄, while iron does not dissolve under these conditions.
2. The solution of zinc sulphate can then be subjected to electrolysis or displacement (using Zn dust) to recover pure zinc.
3. Thus, zinc is separated from iron.

\[\ce{Zn + H2SO4 -> ZnSO4 + H2 \uparrow}\]