Question

Justify that the reaction;

2Cu₂O(s) + Cu₂S(s) → 6Cu(s) + SO₂(g) is a redox reaction. Identify the species oxidized, reduced, which acts as oxidation and which acts as reductant.

Answer 1

Writing the oxidation number of each atom above its symbol we have,

Here, in the reaction, the oxidation number of copper decreases from +1 in Cu₂O or Cu₂S to 0 in copper metal, therefore, copper is reduced and is .oxidizing agent or oxidants. Further, the oxidation number of S increases from -2 in Cu₂S to +4 in SO₂. Therefore, sulphur is oxidized. Thus, it is reducing agent of reductant.