The pair of substances that will react together to make copper sulfate (CuSO₄) is:

* Copper (Cu) and a concentrated solution of sulfuric acid (H₂SO₄)

Here's how the reaction proceeds:

Reaction:

Cu(s) + 2H₂SO₄(conc.) → CuSO₄(aq) + SO₂(g) + 2H₂O(l)

Explanation:

* Copper reacts with concentrated sulfuric acid.

* The sulfuric acid acts as both an oxidizing agent and an acid.

* Copper is oxidized to copper(II) ions (Cu²⁺), while the sulfuric acid is reduced to sulfur dioxide (SO₂).

* The copper(II) ions then react with sulfate ions (SO₄²⁻) from the sulfuric acid to form copper sulfate (CuSO₄).

Important Notes:

* This reaction is a redox reaction (oxidation-reduction).

* The reaction is carried out in a concentrated solution of sulfuric acid because dilute sulfuric acid will not react with copper.

* This reaction generates sulfur dioxide gas (SO₂), which is a toxic and corrosive gas.

Let me know if you have any other questions!