What is an oxidising agent?

An oxidising agent accepts electrons from another substance, causing that substance to be oxidised, while the oxidising agent itself gets reduced.

Memory trick: OIL RIG Oxidation Is Loss, Reduction Is Gain (of electrons).

Common Oxidising Agents: O₂, O₃, H₂O₂, KMnO₄, concentrated H₂SO₄ and HNO₃.

Example: In 2Mg + O₂ → 2MgO, oxygen is the oxidising agent.

An oxidising agent accepts electrons from another substance, causing oxidation of that substance while itself being reduced.