An oxidizing agent (oxidant), gains electrons and is reduced in a chemical reaction. It is also known as electron acceptor. The oxidizing agent is usually in one of its higher possible oxidation states as it will gain electrons and be reduced.
Examples of oxidizing agents are:
- potassium nitrate
- nitric acid
A reducing agent (reductant), loses electrons and is oxidized in a chemical reaction. It is typically in one of its lower possible oxidation states and is known as an electron donor. A reducing agent is oxidized because it loses electrons in the redox reaction.
Examples of reducing agents are:
- formic acid
- the earth metals
- sulfite compounds