Selenite (ion)
{{short description|Anion composed of selenium and oxygen}}
{{distinguish|Selenite (mineral)}}
Image:Selenite-3D-vdW.png of selenite]]
Selenite refers to the anion with the chemical formula {{chem2|SeO3(2−)|auto=1}}. It is the oxyanion of selenium. It is the selenium analog of the sulfite ion, {{chem2|SO3(2−)}}. Thus selenite is pyramidal and selenium is assigned oxidation state +4. Selenite also refers to compounds that contains this ion, for example sodium selenite {{chem2|Na2SeO3}} which is a common source of selenite.{{cite book|author=F. Fehér|chapter=Sodium Selenite (IV)|title=Handbook of Preparative Inorganic Chemistry, 2nd Ed. |editor=G. Brauer|publisher=Academic Press|year=1963|place=NY, NY|volume=1pages=431}} Selenite also refers to the esters of selenous acid, for example dimethyl selenite {{chem2|(CH3)2SeO3}}.
Synthesis and reactions
Selenite salts can be prepared by neutralizing solutions of selenous acid, which is generated by dissolving selenium dioxide in water. The process proceeds via the hydrogenselenite ion, {{chem2|HSeO3−}}.
Most selenite salts can be formed by heating the metal oxide with selenium dioxide, e.g.:
:{{chem2|Na2O + SeO2 → Na2SeO3}}
References
{{commons category|Selenates}}
{{Selenites}}
{{Selenium compounds}}
Category:Selenium(IV) compounds
{{Chem-stub}}