Tags: Chemical Compound, Chemical Substance.
Magnesium sulfite is the magnesium salt of sulfurous acid with the formula MgSO3. Its most common hydrated form has 6 water molecules making it a hexahydrate MgSO3·6H2O. When heated above 40 °C (104 °F) it is dehydrated to magnesium sulfite trihydrate or MgSO3·3H2O. The anhydrous form is hygroscopic meaning that it readily absorbs water from the air.
