Oxidizing agent

Example of oxidation

The formation of iron(III) oxide;

4Fe + 3O₂ → 2Fe₂O₃

In the above equation, the half-reactions" that occur concurrently:

1. Oxidation Half Reaction: Fe⁰ → Fe³⁺ + 3e⁻
2. Reduction Half Reaction: O₂ + 4e⁻ → 2 O²⁻

Iron III (Fe) has been oxidized because the oxidation number increased and is the reducing agent because it gave electrons to the oxygen (O). Oxygen (O) has been reduced because the oxidation number has decreased and is the oxidizing agent because it took electrons from iron (Fe)

Alternate meanings

Because the process of corrosion), the term oxidizing agent has acquired multiple meanings.

One definition, an oxidizing agent receives - or accepts - electrons from a reagent. In this context, the oxidizing agent is called an electron transfer event, which can be described as inner sphere or outer sphere.

In another more colloquial usage, an oxidizing agent transfers oxygen atoms to the substrate. In this context, the oxidizing agent can be called an oxygenation reagent or oxygen-atom transfer agent. Examples include [MnO₄]⁻ permanganate, [CrO₄]²⁻ manganate.

The strict dangerous goods definition of an oxidizing agent are substances that, while in themselves not necessarily combustible, may, generally by yielding oxygen, cause, or contribute to, the combustion of other material. (Australian Dangerous Goods Code 6th Edition) By this definition some materials that are classified as oxidizing agents by analytical chemists are not classified as oxidizing agents in a dangerous goods sense. An example is potassium dichromate which does not pass the dangerous goods test of an oxidizing agent.