Question

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

Copper and magnesium

Give reasons for your choice.

Answer 1

For the separation of copper and magnesium, the method suggested is Hydrometallurgy (selective leaching).

Reason:

1. Copper is a less reactive metal and its compounds (like CuO, Cu₂S) can be easily dissolved in suitable solvents such as dilute H₂SO₄ or aqueous ammonia with O₂.
2. Magnesium, being a highly reactive metal, does not dissolve under these conditions.
3. Thus, copper goes into solution as Cu²⁺, while magnesium remains unaffected.
4. Copper is then recovered by displacement (using Fe) or electrolysis of the solution.

\[\ce{CuO + H2SO4 -> CuSO4 + H2O}\]