pictogram for oxidizing chemicals.]] In chemistry, an oxidizing agent (oxidant, oxidizer) is a substance that has the ability to oxidize other substances, in other words to cause them to lose electrons. Common oxidizing agents are oxygen, hydrogen peroxide and the halogens. In one sense, an oxidizing agent is a chemical species that undergoes a chemical reaction that removes one or more electrons from another atom. In that sense, it is one component in an oxidation–reduction (redox) reaction. In the second sense, an oxidizing agent is a chemical species that transfers electronegative atoms, usually oxygen, to a substrate. Combustion, many explosives, and organic redox reactions involve atom-transfer reactions.
Electron acceptorsElectron acceptors participate in electron-transfer reactions. In this context, the oxidizing agent is called an electron acceptor and the reducing agent is called an electron donor. A classic oxidizing agent is the ferrocenium ion , which accepts an electron to form Fe(C5H5)2. One of the strongest acceptors commercially available is " Magic blue", the radical cation derived from N(C6H4-4-Br)3. is an organic electron-acceptor.]] Extensive tabulations of ranking the electron accepting properties of various reagents (redox potentials) are available, see Standard electrode potential (data page).
Atom-transfer reagentsIn more common usage, an oxidising agent transfers oxygen atoms to a substrate. In this context, the oxidising agent can be called an oxygenation reagent or oxygen-atom transfer (OAT) agent. Examples include ( permanganate), ( chromate), OsO4 ( osmium tetroxide), and especially ( perchlorate). Notice that these species are all oxides. In some cases, these oxides can also serve as electron acceptors, as illustrated by the conversion of to , manganate.
Common oxidizing agents (O-atom transfer agents)
- Oxygen (O2)
- Ozone (O3)
- Hydrogen peroxide (H2O2) and other inorganic peroxides, Fenton's reagent
- Fluorine (F2), chlorine (Cl2), and other halogens
- Nitric acid (HNO3) and nitrate compounds
- Sulfuric acid (H2SO4)
- Peroxydisulfuric acid (H2S2O8)
- Peroxymonosulfuric acid (H2SO5)
- Chlorite, chlorate, perchlorate, and other analogous halogen compounds
- Hypochlorite and other hypohalite compounds, including household bleach (NaClO)
- Hexavalent chromium compounds such as chromic and dichromic acids and chromium trioxide, pyridinium chlorochromate (PCC), and chromate/dichromate compounds
- Permanganate compounds such as potassium permanganate
- Sodium perborate
- Nitrous oxide (N2O)
- Potassium nitrate (KNO3), the oxidizer in black powder
- Sodium bismuthate