Sulphates of Hydroxylamine

The normal sulphate of hydroxyl- amine, (NH₂OH)₂.H₂SO₄, is formed by evaporation of hydroxylamine hydrochloride with the calculated amount of sulphuric acid. It forms large monoclinic prisms, melting at 170° C. With the sulphates of iron, aluminium and chromium, alums are obtained, while with magnesium sulphate a double salt is obtained of the type MgSO₄.[NH₃(OH)]₂SO₄.6H₂O.

The acid sulphate of hydroxylamine, NH₂OH.H₂SO₄, is obtained as long deliquescent prisms when hydroxylamine hydrochloride which has been treated with the quantity of sulphuric acid necessary to form the acid salt is heated for some time to expel all the hydrogen chloride.