Dehydrosulphazotinic Acid, H₄N₂S₄O₁₄

The potassium salt deposits from the blue solution mentioned in the preceding preparation as bright yellow crystals. It is very unstable and is decomposed by water with formation of a new compound having the composition K₃N₂S₃O₁₀:

2K₄N₂S₄O₁₄ + H₂O = 2KHSO₄ + 2K₃N₂S₃O₁₀ + N₂O.