Wackenroder solution

Wackenroder solution is water solution of polythionic acids H₂S_nO₆ (n = 3-20). It is formed by the reaction of hydrogen sulfide (H₂S) with sulfur dioxide (SO₂) in highly dilute aqueous solution. At temperatures above 20 °C solutes slowly decomposes with separation unit sulfur, sulfur dioxide, and sulfuric acid.