Oxyanion Definition in Chemistry

The hypochlorite anion in sodium hypochlorite (bleach) is an example of a common oxyanion.

An anion is an ion that carries a net negative electrical charges. Because the anions are such a large group of ions, they may be further divided according to type. One type of anion is an oxyanion or oxoanion.

Oxyanion Definition

An oxyanion is an anion containing oxygen. The general formula of an oxyanion is AxOyz-, where A is an element symbol, O is an oxygen atom, and x, y, and z are integer values. Most elements can form oxyanions, meeting the conditions of the octet rule.

Oxyanion Examples

Nitrate (NO3-), Nitrite (NO2-), sulfite (SO32-) and hypochlorite (ClO-) are all oxyanions.


  • Mueller, U. (1993). Inorganic Structural Chemistry. Wiley.