When magnesium is placed in a copper sulfate solution, a chemical reaction takes place. Magnesium is more reactive than copper, so it displaces copper ions from the copper sulfate solution. Here's what happens step by step:
Initially, the copper sulfate solution contains copper ions (Cu²⁺) and sulfate ions (SO₄²⁻).
When magnesium (Mg) is introduced into the solution, it undergoes a redox reaction. The magnesium atoms lose electrons and are oxidized, while the copper ions gain electrons and are reduced.
The magnesium atoms lose two electrons each to form magnesium ions (Mg²⁺), which go into the solution. The oxidation half-reaction can be represented as: Mg → Mg²⁺ + 2e⁻.
The copper ions (Cu²⁺) in the solution gain two electrons each and are reduced to form solid copper (Cu). The reduction half-reaction can be represented as: Cu²⁺ + 2e⁻ → Cu.
As the reaction proceeds, the copper ions from the copper sulfate solution are reduced and deposited onto the surface of the magnesium. The solid copper appears as a reddish-brown coating on the magnesium.
In summary, the magnesium is oxidized and releases electrons, while the copper ions are reduced and form a solid copper coating on the magnesium. This reaction demonstrates a displacement reaction where a more reactive metal (magnesium) displaces a less reactive metal (copper) from its compound (copper sulfate).