IUPAC name: Sodium chlorate (III)
Other names: Sodium chlorite; chlorous acid sodium salt..
CAS number: 7758-19-2
Sodium chlorite is a sodium salt of chlorous acid and a powerful oxidant. It is more stable than sodium chlorate, and indeed it does not decompose by friction. The anhydrous salt is not hygroscopic and is stable over several years if properly stored. In a dry state, chlorites are stable at room temperature; they decompose violently when heated above 100 °C.
The main compounds used to manufacture sodium chlorite are chlorine dioxide and sodium hydroxide.
The chlorine dioxide is made to bubble through a caustic soda solution, yielding sodium chlorite and sodium chlorate in approximately equal quantities. A reducing agent (hydrogen peroxide is used industrially) is utilised to decrease the production of sodium chlorate. The compound is purified by fractional crystallisation, taking advantage of the different solubility of the chlorate and chlorite. A product of very high purity is obtained by this method.
Sodium chlorite is utilised in many sectors.