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.
It may also be obtained by heating carbon, sulphur and many metals with concentrated sulphuric acid: C + 2H 2 SO 4 = 2SO 2 }- CO 2 + 2H 2 O; S + 2H 2 SO 4 = 3S0 2 + 2H 2 0; Cu + 2H 2 SO 4 = SO 2 -fCuSO 4 + 2H 2 0; and by decomposing a sulphite, a thiosulphate or a thionic acid with a dilute mineral 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.