Question

Which of the following oxides can act both as an oxidising agent as well as reducing agent?

Options

• N₂O

• SO₂

• SO₃

• P₂O₅

Answer 1

SO₂

Explanation:

SO₂ oxides can act both as an oxidising agent as well as a reducing agent. It behaves as a reducing agent in moist conditions. It converts iron (Ill) ions to iron (II) ions and decolourises acidified potassium permanganate (VII) solution.

\[\ce{2Fe^{3+} + SO2 + 2H2O -> 2Fe^{2+} + SO^{2-}_4 + 4H+}\]

When SO₂ reacts with H₂S, it produces sulphur and water. In this reaction, 'SO₂' act as an oxidising agent.