Hydrides of sulfur sulfanes

Hydrogen sulfide is the only thermodynamically stable sulfane it occurs widely in nature as a result of volcanic or bacterial action and is, indeed, a prime source of elemental 8 (p. 647). It has been known since earliest times and its classical chemistry has been extensively studied since the seventeenth century.H28 is a foul smelling, very poisonous gas familiar to all students of chemistry. Its smell is noticeable at 0.02 ppm but the gas tends to anaesthetize the olefactory senses and the intensity of the smell is therefore a dangerously unreliable guide to its concentration. H28 causes irritation at 5 ppm, headaches and nausea at 10 ppm and immediate paralysis and death at 100 ppm it is therefore as toxic and as dangerous as HCN. 

H28 is readily prepared in the laboratory by treating Fe8 with dilute HCl in a Kipp apparatus. Purer samples can be made by hydrolysing Ca8, Ba8 or AI283, and the purest gas is prepared by direct reaction of the elements at 600°C. 

Mellor, a Comprehensive Treatise on Inorganic and Theoretical Chemistry, Vol. 10, pp. 114-61, Longmans, London, 1930. 

8ome physical properties are in Table 15.11 comparison with the properties of water (p. 623) shows the absence of any appreciable H bonding in H28.O ) Comparisons with H28e, H2Te and H2P0 are on p. 767. 

H28 is readily soluble in both acidic and alkaline aqueous solutions. Pure water dissolves 4.65 volumes of the gas at 0° and 2.61 volumes at 20° in other units a saturated solution is 0.1 M at atmospheric pressure and 25°, i.e. 

02 ppm but the gas tends to anaesthetize the olefactory senses and the intensity of the smell is therefore a dangerously unreliable guide to its concentration. H2S causes irritation at 5 ppm, headaches and nausea at 10 ppm and immediate paralysis and death at 100 ppm it is therefore as toxic and as dangerous as HCN. 

---