Nitrososulphonic Acid, N(NO)(OH)SO₃H

The sodium salt of Nitrososulphonic Acid or Nitrosohydroxylamine-sulphonic Acid, N(NO)(OH)SO₃H or HO₂N₂SO₃H, has been prepared by the action of nitric oxide on a caustic soda solution of sodium sulphite:

Na₂SO₃ + 2NO = Na₂SN₂O₅.

The alkali nitrososulphonates are decomposed by acids with formation of nitrous oxide and the corresponding sulphate. With barium chloride the nitrososulphonates yield a white precipitate which is soluble in hydrochloric acid.