Sulphides monosulphides

Ferrous sulphide 4053. 4147 PeS iron sulphide monosulphide of iron pro-tosulphlde of iron sulphide of iron suiphuret of iron. 

Fig. 8.6. Course of the CBS-accelerated sulphur vulcanization of natural rubber at 140T with a high sulphur accelerator ratio (2-5 0-6). (x) Total cross-links ( ) poly sulphide ( ) monosulphide ( ) disulphide. The upper and lower figures on the curve relating to total cross-links are values of E and E, respectively. (After Moore, 1965.)...

Figure 11.15. Typical chemical groupings in a sulphur-vulcanised natural rubber network, (a) Monosulphide cross-link (b) disulphide cross-link (c) polysulphide cross-link (j = 3-6) (d) parallel vicinal cross-link (n = 1-6) attached to adjacent main-chain atoms and which have the same influence as a single cross-link (e) cross-links attached to common or adjacent carbon atom (f) intra-chain cyclic monosulphide (g) intra-chain cyclic disulphide (h) pendent sulphide group terminated by moiety X derived from accelerator (i) conjugated diene (j) conjugated triene (k) extra-network material (1) carbon-carbon cross-links (probably absent)...

Iron sulphides are ubiquitous in marine and freshwater sediments. They are usually present either as pyrite or as monosulphides, which can be liberated by hydrochloric acid. These acid volatile sulphides give rise to an intense black colour that is characteristic of anoxic sediments. They play an important role in recent diagenetic processes in sediments and the ratio of pyrite to acid volatile sulphides has been used as an historical indicator to determine whether sediments were formed in marine or freshwater conditions. They can be present over a wide range of... 

The few cases reported for CD sulphides and selenides of T1 all reported the monosulphide (selenide)—TIS or TlSe. T1 can be monovalent or trivalent, and these apparently divalent compounds are believed to be mixed-valence compounds, with both T1(I) and Tl(III) present. 

G. Taddei7 prepared potassium iodide by adding a dil. soln. of potassium monosulphide to an alcoholic soln. of iodine. In place pf potassium sulphide, J. von Liebig and C. Wittstock used barium sulphide, prepared by calcining sulphate with coke. According to R. Schindler, the products obtained by the sulphide process are contaminated with sulphur compounds. G. S. Serullas treated potassium antimoniate (prepared by calcining tartar emetic) with an alcoholic soln. of iodine as long as the soln. was decolorized. The filtered soln. was evaporated to the point of crystallization. 

The preparation of the alkali monosulphides.—Products usually called sulphides have been obtained by the direct union of the elements. Thus, L. Troost 2 prepared what he regarded as amorphous lithium sulphide, Li2S, by the action of sulphur vapour on heated lithium. H. Davy, and J. L. Gay Lussac and L. J. Thenard, prepared sodium sulphide, Na2S, by warming sulphur with sodium ... 

J. J. Berzelius melted sulphur with an excess of potassium hydroxide and found the product to be a mixture of the monosulphide and thiosulphate. J. Kircher passed hydrogen sulphide over coarsely powdered sodium hydroxide at 100°. M. J. Fordos and A. Gelis made sodium sulphide by heating sodium carbonate with sulphur to 275° the product is obviously a kind of soda-liver of sulphur. J. W. Kynaston melted sodium hydroxide With calcium sulphide and J. V. Esop, and C. Vincent treated a soln. of barium or other sulphide with sodium or potassium... 

H. Riesenfeld found the solubility of ammonia in soln. of sodium sulphide to be a linear function of the Na2S-conc. and they measured the ammonia press, of A-soln. of ammonia in sodium sulphide. With soln. containing 0 5, 1, and 1 5 mol. of sodium monosulphide, the respective press, of the ammonia were 15 18, 16 94, and 18 55 mm., when the press, of the ammonia in 2V-aq. soln. was 13 45 mm. According to W. P. Bloxam, potassium sulphide is stable at a low red heat and does not decompose when it is melted. P. Berthier stated that it is volatilized at high temp. When it is roasted in the air, potassium sulphide... 

H. Bottger has said that when a soln. of the alleged sodium pentasulphide is boiled with head hydroxide, it behaves like a mixture of sulphur and sodium monosulphide, for lead sulphide and sodium thiosulphate are produced he adds that in... 

Hence, to prepare a cone. soln. of ammonium monosulphide, a current of washed hydrogen sulphide is passed into cone, aqua ammonia cooled to 0° until the neutral point is reached. Attempts to obtain crystals by cooling the soln. to —40° were not successful. W. P. Bloxam believes that the soln. so obtained is not really the monosulphide at all, but rather a soln. of a mol. of the complex (NH4)2S.2NH4SH in two mols. of ammonium hydroxide, NH4OH because of (i) its action on cupric sulphate (ii) its failure to yield crystals by cooling, attributed to the solvent action of free ammonia and (iii) because it exhibits no tendency to dissolve sulphur. 

The methods which have been reported for preparation of ammonium disulphide, (NIL Sa, by the dissolution of the theoretical amount of sulphur in ammonium monosulphide, were specially studied by W. P. Bloxam6 in his memoir The sulphides and polysulphides of ammonium. He sealed up the calculated quantify of sulphur in a tube with a soln. of ammonium monosulphide. He noticed an evolution of gas occurred as the sulphur dissolved, a phenomenon which he thinks would not be observed if (NH4)2S were really the solute. W. P. Bloxam also failed to obtain the disulphide by passing through a hot tube the vapour of ammonium chloride and sulphur, and he finally concluded that up to the present ammonium disulphide has not been prepared either in the solid state or in soln. J. Fritzsche also failed to make the disulphide nearly 60 years earlier than W. P. Bloxam. B. de Fororand calculated that the heat of formation of the Unknown solid will prove to be>(N2,H8,S2)8oUd=(NH4)iiS23oUd+66-2 Cals. 

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