Hydrogen sulfite (bisulfite) ion (HSO₃⁻)
- Charge
- −1
- Atoms
- H, S, O × 3
- Atoms in total
- 5
- Mass of the ion
- 81.065 g/mol
Hydrogen sulfite, usually called bisulfite, is one hydrogen, one sulfur and three oxygen atoms with a 1− charge. It is a sulfite ion, SO₃²⁻, that still carries one hydrogen ion, which cancels one of its two negative charges. It forms when sulfur dioxide dissolves in water and is used to preserve food and wine and to remove chlorine from treated water.
- Bi- is the older prefix for hydrogen in ion names, as in bicarbonate and bisulfate.
- Hydrogen sulfite exists mainly in solution; when its salts are dried, pairs of ions lose water and form metabisulfite, S₂O₅²⁻.
- Sodium hydrogen sulfite, NaHSO₃, is a common food preservative and dechlorinating agent.
Compounds that contain hydrogen sulfite (bisulfite)
NaHSO3 Sodium hydrogen sulfite
KHSO3 Potassium hydrogen sulfite
Ca(HSO3)2 Calcium hydrogen sulfite