They are precipitated from their alkaline solutions as cobalt sulphide by sulphuretted hydrogen, but this precipitation is prevented by the presence of citric and tartaric acids; similarly the presence of ammonium salts hinders their precipitation by caustic alkalis.
Certain yeasts exercise a reducing action, forming sulphuretted hydrogen, when sulphur is present.
By the addition of sulphuretted hydrogen to the nitriles, or by the action of phosphorus pentasulphide on the acid-amides.
It forms slightly coloured small crystals possessing a strong disagreeable smell, and is rapidly decomposed by water with the formation of boric acid and sulphuretted hydrogen.
A pentasulphide B2S5 is prepared, in an impure condition, by heating a solution of sulphur in carbon bisulphide with boron iodide, and forms a white crystalline powder which decomposes under the influence of water into sulphur, sulphuretted hydrogen and boric acid.
Simultaneously Hermann, a German chemical manufacturer, discovered the new metal in a specimen of zinc oxide which had been thought to contain arsenic, since it gave a yellow precipitate, in acid solution, on the addition of sulphuretted hydrogen.
Cadmium sulphide, CdS, occurs naturally as greenockite (q.v.), and can be artificially prepared by passing sulphuretted hydrogen through acid solutions of soluble cadmium salts, when it is precipitated as a pale yellow amorphous solid.
It is used as a pigment (cadmium yellow), for it retains its colour in an atmosphere containing sulphuretted hydrogen; it melts at a white heat, and on cooling solidifies to a lemon-yellow micaceous mass.
Cadmium salts can be recognized by the brown incrustation which is formed when they are heated on charcoal in the oxidizing flame of the blowpipe; and also by the yellow precipitate formed when sulphuretted hydrogen is passed though their acidified solutions.
It can also be determined as sulphide, by precipitation with sulphuretted hydrogen, the precipitated sulphide being dried at Ioo° C. and weighed.
Molybdenum disulphide, MoS 2, is found as the mineral molybdenite, and may be prepared by heating the trioxide with sulphur or sulphuretted hydrogen.
Molybdenum trisulphide, MoS3, is obtained by saturating a solution of an alkaline molybdate with sulphuretted hydrogen and adding a mineral acid.
It can also be obtained by passing sulphuretted hydrogen through a solution of the dioxide in hydrochloric acid.
The germanium salts are most readily recognized by the white precipitate of the disulphide, formed in acid solutions, on passing sulphuretted hydrogen.
Sulphur dioxide and sulphuretted hydrogen are present in volcanic exhalations and in many mineral waters.
Rhombic sulphur may be obtained artificially by slowly crystallizing a solution of sulphur in carbon bisulphide, or, better, by exposing pyridine saturated with sulphuretted hydrogen to atmospheric oxidation (Ahrens, Ber., 1890, 23, p. 2708).
The colloidal sulphur, Ss, described by Debus as a product of the interaction of sulphuretted hydrogen and sulphur dioxide in aqueous solution, is regarded by Spring (Rec. tra y.
Sulphuretted hydrogen, H 2 S, a compound first examined by C. Scheele, may be obtained by heating sulphur in a current of hydrogen, combination taking place between 200° C. and 358° C., and being complete at the latter temperature, dissociation taking place above this temperature (M.
To obtain pure sulphuretted hydrogen the method generally adopted consists in decomposing precipitated antimony sulphide with concentrated hydrochloric acid.
Sulphuretted hydrogen is a colourless gas possessing an extremely offensive odour.
Oxidizing agents rapidly attack sulphuretted hydrogen, the primary products of the reaction being water and sulphur.
It may be condensed and yields a solid which melts at - 55° C. Sulphuretted hydrogen decomposes it with formation of hydrofluoric acid and liberation of sulphur.
News, 1902, 86, p. 5) obtained a substance of composition S312 (which in all probability is a chemical individual) as a reddish-coloured powder by the action of sulphuretted hydrogen on a solution of iodine trichloride.
Soc., 1888, 53, p. 278) is prepared by passing sulphuretted hydrogen gas into a nearly saturated aqueous solution of sulphur dioxide at about o° C. The solution is then allowed to stand for 48 hours and the process repeated many times until the sulphur dioxide is all decomposed.
It is then converted into the lead salt, which is decomposed by sulphuretted hydrogen and the solution is carefully concentrated (Th.
Natural gas is found to consist mainly of the lower paraffins, with varying quantities of carbon dioxide, carbon monoxide, hydrogen, nitrogen and oxygen, in some cases also sulphuretted hydrogen and possibly ammonia.
Many of the springs have curative properties, one of them, the Green Cove Spring in Clay county, discharging about 3000 gallons of sulphuretted water per minute.
It may be more conveniently prepared by passing the vapour of sulphur over red hot charcoal, the unccndensed gases so produced being led into a tower containing plates over which a vegetable oil is allowed to flow in order to absorb any carbon bisulphide vapour, and then into a second tower containing lime, which absorbs any sulphuretted hydrogen.
When heated with water in a sealed tube to 150° C. it yields carbon dioxide and sulphuretted hydrogen.
A mixture of carbon bisulphide vapour and sulphuretted hydrogen, when passed over heated copper, gives, amongst other products, some methane.
Aqueous and alcoholic solutions of ammonia convert carbon bisulphide into ammonium dithiocarbamate, which readily breaks down into ammonium thiocyanate and sulphuretted hydrogen (A.
Zn(OK)2] Zinc oxide is used in the arts as a white pigment (zinc white); it has not by any means the covering power of white lead, but offers the advantages of being non-poisonous and of not becoming discoloured in sulphuretted hydrogen.
Tin dissolves readily in strong hot hydrochloric acid as SnC12; aqueous sulphuric acid does not act on it appreciably in the cold; at 150° it attacks it more or less quickly, according to the strength of the acid, with evolution of sulphuretted hydrogen or, when the acid is stronger, of sulphurous acid gas and deposition of sulphur (Calvert and Johnson).
Silicon sulphide, SiS 2, is formed by the direct union of silicon with sulphur; by the action of sulphuretted hydrogen on crystallized silicon at red heat (P. Sabatier, Comptes rendus, 1880, 90, p. 819); or by passing the vapour of carbon bisulphide over a heated mixture of silica and carbon.
The oil separates from the fat-cells and is found lying free, while the sulphuretted hydrogen evolved as one of the products of putrefaction reacts upon the iron of the blood and throws down a precipitate of sulphide of iron, which in course of time imparts to the limb a range of colour commencing in green and terminating in black.
Stannous sulphide, SnS, is obtained as a lead-grey mass by heating tin with sulphur, and as a brown precipitate by adding sulphuretted hydrogen to a stannous solution; this is soluble in ammonium polysulphide, and dries to a black powder.
Stannic sulphide, SnS 2, is obtained by heating a mixture of tin (or, better, tin amalgam), sulphur and sal-ammoniac in proper proportions in the beautiful form of aurum musivum (mosaic gold) - a solid consisting of golden yellow, metallic lustrous scales, and used chiefly as a yellow "bronze" for plaster-of-Paris statuettes, &c. The yellow precipitate of stannic sulphide obtained by adding sulphuretted hydrogen to a stannic solution readily dissolves in solutions of the alkaline sulphides to form thiostannates of the formula M 2 SnS 31 the free acid, H2SnS3, may be obtained as an almost black powder by drying the yellow precipitate formed when hydrochloric acid is added to a solution of a thiostannate.
Stannous salt solutions yield a brown precipitate of SnS with sulphuretted hydrogen, which is insoluble in cold dilute acids and in real sulphide of ammonium, (NH 4) 2 S; but the yellow, or the colourless reagent on addition of sulphur, dissolves the precipitate as SnS 2 salt.
Stannic salt solutions give a yellow precipitate of SnS 2 with sulphuretted hydrogen, which is insoluble in cold dilute acids but readily soluble in sulphide of ammonium, and is re-precipitated therefrom as SnS2 on acidification.
From the solution the arsenic, copper, &c., are precipitated by sulphuretted hydrogen as sulphides, which are filtered off.
Solutions of uranyl salts (nitrate, &c.) behave to reagents as follows: sulphuretted hydrogen produces green uranous salt with precipitation of sulphur; sulphide of ammonium in neutral solutions gives a black precipitate of UO 2 S, which settles slowly and, while being washed in the filter, breaks up partially into hydrated UO 2 an sulphur; ammonia gives a yellow precipitate of uranate of ammonia, characteristically soluble in hot carbonate of ammonia solution; prussiate of potash gives a brown precipitate which in appearance is not unlike the precipitate produced by the same reagent in cupric salts.
It is a white amorphous infusible powder, which when strongly heated in sulphuretted hydrogen, yields an oxysulphide.