Sulphazinic Acid, [N(OH)(SO₃H)]₂O

The potassium salt of Sulphazinic Acid, [N(OH)(SO₃H)]₂O, is formed when a stream of sulphur dioxide is passed through a concentrated solution of potassium nitrite. On standing, the salt decomposes to the hydroxylamine disulphonate and nitrite:

KHN₂O₃(SO₃K)₂ = N(OH)(SO₃K)₂ (Potassium hydroxylamine disulphonate.) + KNO₂.