Chemistry:Selenite (ion)

Short description: Anion composed of selenium and oxygen

Structure of selenite

Space-filling model of selenite

The selenite anion is a selenium oxoanion with the chemical formula SeO2−3.

A selenite (compound) is a compound that contains this ion.

In slightly acid conditions, the hydrogenselenite ion, HSeO−3, is formed; in more acidic conditions selenous acid, H₂SeO₃, exists.

Most selenite salts can be formed by heating the relevant metal oxide with selenium dioxide, e.g.:

Na₂O + SeO₂ → Na₂SeO₃.