Barium Hydrosulphide, Ba(SH)₂

Barium Hydrosulphide, Ba(SH)₂, is formed by passing sulphuretted hydrogen into a saturated barium hydroxide solution at 60°-70° C., and then cooling, or by dissolving barium sulphide in sulphuretted hydrogen water. By evaporation of the solution in vacuo in the cold, or by precipitation with alcohol, white, opaque, needle-shaped crystals are obtained containing 4 molecules of water, Ba(SH)₂.4H₂O. When heated in hydrogen they lose water and a little sulphuretted hydrogen above 55° C., but when the substance is dehydrated its stability is increased. It is only at red heat that sulphuretted hydrogen is completely eliminated and barium sulphide formed.

Solutions of barium hydrosulphide have a considerable partial pressure of sulphuretted hydrogen. Determinations of the solubility in water between -15° C. and 100° C. have been made in closed tubes to prevent the escape of sulphuretted hydrogen.

Temperature, °C.	-15	0	20	40	60	80	100
Grams Ba(SH)2 per 100 grams solution	32	32.6	32.8	34.5	36.2	39.0	43.7