Hydroxylamine-monosulphonic Acid, NH(OH).SO₃H

Hydroxylamine-monosulphonic Acid, NH(OH).SO₃H has been very completely studied by Raschig. The sodium salt is formed according to the following reactions:

1) NaNO₂ + NaHSO₃ + SO₂ = HO.N(SO₃Na)₂,

2) HO.N(SO₃Na)₂ + H₂O = HO.NH.SO₃Na + NaHSO₄.

The free acid is very stable. Hot alkalis decompose it according to the equations:

1) 3NH(OH)(SO₃K) + 3KOH = N₂ + NH₃ + 3K₂SO₄ + 8H₂O,
or
2) 4NH(OH)(SO₃K) + 4KOH = N₂O + 2NH₃ + 4K₂SO₄ + 3H₂O.