Hydrogen sulphide sulphite

Arsenates(V) are more powerful oxidising agents than phos-phates(V) and will oxidise sulphite to sulphate, hydrogen sulphide (slowly) to sulphur and, depending on the conditions, iodide to iodine. 

Further reaction between hydrogen sulphide and the sulphite ion yields sulphur together with thionic acids) ... 

Salmonella typhi, in the presence of glucose, reduces bismuth sulphite to bismuth sulphide, a black compound the organism can produce hydrogen sulphide from sulphur-containing amino acids in the medium and this will react with ferrous ions to give a black deposit of ferrous sulphide (Table 1.2). 

BorreU L, Cervera-March S, Gimenez J, Simarro R, Andujar JM (1992) A comparative study of CdS-based semiconductor photocatalysts for solar hydrogen production from sulphide + sulphite substrates. Sol Energy Mater Sol Cells 25 25-39... 

Takemoto BK, Noble RD, Harrington HM. 1986. Differential sensitivity of duckweeds (Lemnaceae) to sulfite II. Thiol production and hydrogen sulphide emission as factors influencing sulphite phytotoxicity under low and high irradiance. New Phytologist 103 541-548. 

Subrahmanyam, M., Supriya, V.T., and Reddy, P.R., Photocatalytic H2 production with CdS-based catalysts from a sulphide/sulphite An effort to develop MgO-supported catalysts, Int.. Hydrogen Energ., 21, 99,1996. 

According to G. Calcagni, 100 c.c. of a cold 66 per cent, of sodium hydroxide dissolves 24 55 grms. of sulphur or 57 parts of sulphur per 23 parts of sodium while 100 c.c. of a similar soln. of potassium hydroxide dissolves 17 70 grms. of sulphur, or 59 35 parts of sulphur per 39 15 parts of potassium. The soln. reacts for sulphides, polysulphides, thiosulphates, and sulphites. The reaction between alkali hydroxides and sulphur is complex probably sulphides are first formed from which thiosulphates are produced, and by the dissolution of more sulphur, polysulphides the thiosulphates Ipse part of their sulphur forming sulphites. In the more cone. soln. of sulphur part of the latter appears to be uncombined because these soln. yield sulphur to hot benzene. All the soln. are decomposed by carbon dioxide yielding sulphur and hydrogen sulphide. 

The various kinds of alkali, cf commerce usually contain a. greater or less proportion of chlorides and sulphates. The presence of these dees not interfere In the slightest degree with the above methods of estimation. In some cases, however, sulphides, sulphites, and hyposulphites aro also present, and these, neutralizing a certain quantity of the tost acjd, Tender the determinations more or less inaccurate. The first of these salts evolves sulphide of hydrogen, the second sulphurous acid, and the last hyposulphurous acid, which is immediately decomposed into sulphurous ecitl... 

Hydrogen sulphide is present in many mineral springs, and even free sulphur is occasionally found therein.2 Many metallic sulphides, for example, iron pyrites, galena, zinc blende, stibnitc and cinnabar, occur abundantly. Sulphur dioxide, sulphites, sulphuric acid and sulphates are also found in nature, more especially in waters springing from volcanic earth, whilst the sulphates of certain metals such as calcium, barium and magnesium exist in large deposits. 

The main polysulphide products are trisulphide, tetrasulphide and pentasulphide, but on account of the tendency of the polysulphides to decompose, yielding thiosulj hate and hydrogen sulphide, the quantity of thiosulphate usually exceeds that indicated in the equation.7 Loss of sulphur by the thiosulphate yields sulphite.8 The so-called lime-sulphur washes, used as insecticides in agricultural work, are obtained by treating sulphur with milk of lime in this way.9... 

From Sulphur-Oxygen Compounds.—Sulphites in aqueous solution are easily reduced to hydrogen sulphide by nascent hydrogen, produced, for example, by the interaction of zinc and dilute sulphuric acid ... 

The reduction of sulphites and of sulphates can also be effected by certain bacteria, the presence of hydrogen sulphide in some mineral waters probably being due to reduction of calcium sulphate in this way.10 The first product is probably the corresponding sulphide, which subsequently undergoes hydrolytic decomposition. 

A similar result is achieved by treating an alkali sulphite in aqueous solution with hydrogen sulphide, the formation of sulphur probably occurring as the first stage 7 (see p. 194). 

Also, in the preparation of the thiosulphate from sodium sulphide and sulphur dioxide, or from sodium sulphite and hydrogen sulphide, as already described, if sodium hydroxide is first added to the solution in such quantity as to lead to the ultimate formation of the hydrogen sulphide and hydrogen sulphite salts in the proportions mentioned, then the reaction proceeds very smoothly and almost without separation of sulphur. 

This equilibrium affords an explanation for the fact that a trace of hydrogen sulphide accelerates the reaction between sodium sulphite and sulphur 4 sometimes there is a long delay before sulphur begins to dissolve in boiling sodium sulphite solution, and in such cases the effect of passing a few bubbles of hydrogen sulphide into the solution is very marked when once the reaction begins it proceeds smoothly. ... 

This seems to suggest that the sulphur unit is S2. This unit is capable of uniting with hydrogen sulphide to form the trisulphide, H2S3 but sodium sulphite can only combine with one atom of sulphur to yield thiosulphate. The catalytic activity of the hydrogen sulphide would thus appear to be due to its ability to absorb a whole sulphur unit, Sa, and subsequently to give up, on reduction, each atom of sulphur separately, thus ... 

Reduction by zinc dust yields an oil iodine in chloroform has no action, but chlorine in the same solvent gives selenium tetrachloride and chloroacetylacetone, and bromine yields lachrymatory products and a colourless crystalline substance of melting-point 180° C. Aqueous hydrogen sulphide causes slow decomposition, with liberation of sulphur and selenium. Potassium metabisulphite and sodium hydrogen sulphite transform selenium acetylacetone quantitatively into alkali selenodithionates, a reaction which affords the best known means of preparing these salts. 

Sulphur colouring matters are more or less soluble in water, but readily soluble in alkalies or alkaline sulphides when treated with hydrochloric acid or, better, with hydrochloric add and stannous chloride, they emit hydrogen sulphide when burnt they give an odour of sulphur dioxide and leave a more or less abundant residue containing alkaline sulphates and sulphites. 

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