Hydrated sodium sulphide

Thiophenoxytellurine. To 0.8 g (0.002 mol) of the dichloride, 7.2 g (0.03 mol) of hydrated sodium sulphide were added and heated at 100°C for 15 min. The reaction mixture was diluted with water and the product filtered and dried (0.6 g, 96%). Recrystallization from ethanol gave pale yellow needles, m.p. 122-123.5°C. 

Anhydrous sodium sulphide. The hydrated salt, NajS.QH O, is heated in a Pyrex distilling flask or retort in a stream of hydrogen or of nitrogen until water ceases to be evolved. The solid cake of anhydrous sodium sulphide is removed from the vessel with the aid of a copper wire hook or by other suitable means. No attempt should be made to fuse the sodium sulphide since at high temperatiues sodium sulphide is readily oxidised to sodium sulphate. 

With sodium sulphide hydrate (general procedure) The diorganyltellurium dihalide is mixed with a 15 times molar excess of Na2S 9H2O and the mixture heated at 95-100°C for 10 min or more, until aU the solid has melted. Sufficient HjO is added to dissolve the sulphide and then the mixture is filtered if the obtained telluride is a solid, or extracted with a solvent (ether or petroleum ether) if the telluride is a liquid. The products are purified by crystallization or distillation. Yields are high or quantitative (except for diphenyl telluride or di-p-tolyl telluride). 

The low temp, form is the more expansible, and has the higher sp. ht. The specific gravity of crystalline lithium sulphide, according to A. Mourlot, ranges from l-63 to 1 70 E. Filhol gives 2-471 for sodium sulphide, and 2 13 for potassium sulphide— E. Filhol s numbers presumably refer to the hydrated salts. O. Boch s values for the sp. gr. of aq. soln. arq indicated below. 

After filtration, addition of sodium sulphide to the clear solution effects the precipitation of the three metals, cobalt, nickel, and manganese, as sulphides. Digestion with the calculated quantity of ferric chloride oxidises the manganese sulphide to sulphate, which passes into solution. The residue consists of cobalt and nickel sulphides, which are washed and converted into their soluble sulphates by roasting. The sulphates are extracted with water, and converted into chlorides by addition of calcium chloride solution. Their separation is effected g.s follows The requisite fraction of the chloride solution is precipitated with milk of lime, and the insoluble hydroxides of nickel and cobalt thus obtained are oxidised to the black hydroxides by treatment with chlorine. The. washed precipitate is then introduced into the remainder of the chloride solution, and the whole is well stirred and heated, when the black hydrated oxide of nickel passes, into solution, displacing tlm Remainder of. the cobalt from the solution, into. the precipitate.. The final product is thus a suspension of hydrated peroxide.of cobalt,in p. solution of nickel chloride, from which idle cobalt precipitate is removed by filtration, washed, and ignited, to the black oxide. 

The most employed reducing agents in the old tellurium chemistry were alkali sulphites or hydrogen sulphites, methyhnagnesium iodide and sodium sulphide hydrate. The last reagent is still used, together with the more recently introduced sodium borohydride, TUDO, hydrazine, samarium diiodide and sodium ascorbate. ... 

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