It is not very stable, water decomposing it into alcohol and the alkaline carbonate.
To obtain pure sulphuretted hydrogen the method generally adopted consists in decomposing precipitated antimony sulphide with concentrated hydrochloric acid.
Thionyl fluoride, SOF 21 has been obtained as a fuming, gas by decomposing arsenic fluoride with thionyl chloride (Moissan and Lebeau, Corn pt.
This solution is yellow in colour, and is very unstable decomposing at ordinary temperature into sulphur and sulphur dioxide.
A solution of the free acid may be obtained by decomposing the barium salt with dilute sulphuric acid and concentrating the solution in vacuo until it attains a density of about 1.35 (approximately), further concentration leading to its decomposition into sulphur dioxide and sulphuric acid.