Sulphur vapour

This was formerly manufactured by passing sulphur vapour over white hot coal or charcoal. An equilibrium was established and the carbon disulphide vapour was condensed, allowing the reaction to proceed ... 

Large quantities are now manufactured by the reaction between sulphur vapour and methane at a temperature of 900-1000 K in the presence of a clay catalyst ... 

The purest form is obtained by passing a mixture of sulphur vapour and hydrogen over finely divided niekel at 450°C. 

The behaviour of nickel is very dependent upon the type of sulphidising gas that is used, and the effects of sulphur vapour, hydrogen sulphide. 

Dilute binary alloys of nickel with elements such as aluminium, beryllium and manganese which form more stable sulphides than does nickel, are more resistant to attack by sulphur than nickel itself. Pfeiffer measured the rate of attack in sulphur vapour (13 Pa) at 620°C. Values around 0- 15gm s were reported for Ni and Ni-0-5Fe, compared with about 0-07-0-1 gm s for dilute alloys with 0-05% Be, 0-5% Al or 1-5% Mn. In such alloys a parabolic rate law is obeyed the rate-determining factor is most probably the diffusion of nickel ions, which is impeded by the formation of very thin surface layers of the more stable sulphides of the solute elements. Iron additions have little effect on the resistance to attack of nickel as both metals have similar affinities for sulphur. Alloying with other elements, of which silver is an example, produced decreased resistance to sulphur attack. In the case of dilute chromium additions Mrowec reported that at low levels (<2%) rates of attack were increased, whereas at a level of 4% a reduction in the parabolic rate constant was observed. The increased rates were attributed to Wagner doping effects, while the reduction was believed to result from the... 

By means of water fire may be extinguished, and utterly quenched. If much water be poured upon a little fire, the fire is overcome, and compelled to yield up the victory to the water. In the same way our fiery sulphur must be overcome by means of our prepared water. But, after the water has vanished, the fiery life of our sulphurous vapour must triumph, and again obtain the victory. But no such triumph can take place unless the King imparts great strength and potency to his water and tinges it with his own colour, that... 

With Sulphur.—If a mixture of sulphur vapour and hydrogen is passed through a tube heated to at least 250° C, a chemical union of the two elements takes place, in accordance with the equation—... 

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 ... 

Preparation of Metal Sulphides from the Elements. Perform the experiment in a fume cupboard ) Copper Sulphide. Fill one-third of a test tube with sulphur and heat it up to boiling. The sulphur vapour should fill the entire tube. Hold a piece of copper gauze or foil with pincers, heat it in the flame of a burner until red hot, and rapidly introduce it into the sulphur vapour. What happens Write the equation of the reaction. How does copper snlphide react with water and hydrochloric acid ... 

Sulphur vapour, at low temperatures, mostly contains the molecules S8 because the angle between the S—S bonds must be about 100°, the S atoms cannot lie in a flat ring but must be folded in a so-called Archimedian antiprism (see Figure 37). In the nitrogen group there are more numerous possibilities, such as ... 

Vapour density experiments conducted under reduced pressure and at temperatures below the normal boiling-point of sulphurhave shown that under such conditions sulphur vapour gradually approaches the octa-atomic condition as the temperature is lowered this is indicated by the following figures ... 

The presence of the u- and 7r-modifieations of sulphur dissolved in molten A-sulphur naturally causes a depression of the freezing-point of the latter, and from the magnitude of this effect it has been possible to demonstrate the probability of a molecular weight corresponding to S6 for the dark brown p.-allotrope, a result which is of especial interest as correlating this form of liquid sulphur with the hexatomic sulphur believed to occur in sulphur vapour (see before).3... 

Flowers of sulphur (see p. 12), when freshly prepared, commonly contains about. 80 per cent, of insoluble sulphur, but this percentage may vary considerably.7 However, if sulphur vapour is condensed on the surface of cold water or especially on the surface of a cold aqueous solution of a mineral acid such as sulphuric acid, the proportion of the insoluble amorphous modification in the deposit may be so high as to render it the main constituent,8... 

Highly dispersed sols, containing up to 0-082 per cent, of sulphur, may be obtained 3 by passing superheated sulphur vapour, free from air, into air-free water. The sols have an acid reaction due to traces of polythionic acids and hydrogen sulphide. They are white and remain stable for several weeks. 

Mondain-Monval and Schneider, Compt. rend., 1928, 186, 1356. For refractive index and dispersion of sulphur vapour, see Cuthbortson and Metcalfe, Proc. Boy. Soc., 1908, [A], 80, 411. For the rofraetivity of sulphur in organic compounds, see Prioe and Twiss, Trans. Chem. 80c., 1912, 101, 1259 Dolfipine, Ann. Chim. Phys., 1912, [viii.], 25, 529. 

The fluorescence spectrum 1 of sulphur vapour under excitation by light from a mercury arc gives a series of bands extending over the visible region. 

The necessary oxygen need not be obtained from the air. Sulphur dioxide is readily obtained by heating sulphur with certain oxides, dioxides or peroxides. Sulphur vapour and steam heated at a suitable temperature in the presence of iron oxide, as catalyst react to form sulphur dioxide and hydrogen which may be recovered separately. With manganese dioxide and powdered sulphur the reaction proceeds as follows ... 

Traces of pentathionic acid are also stated to be found in the condensed liquid from the interaction of steam and sulphur vapour at a red heat,2 and in a mixture of sulphur and water after exposure to atmospheric oxidation.3 In the former ease the pentathionic acid probably results after the high temperature reaction by the interaction of sulphur dioxide and hydrogen sulphide in the condensate. 

Preparation.—Carbon disulphide is prepared by passing sulphur vapour over red hot charcoal. The preparation may be carried out on a small scale by heating pieces of charcoal in a combustion tube placed in a furnace slightly tilted, a Liebig potash bulb, immersed in ice, being attached to the lower end of the tube, and small pieces of sulphur introduced into the upper end of the tube which is then closed with a cork. Sulphur vapour passes over the red-hot charcoal and impure carbon disulphide containing sulphur in solution is gradually formed and collects in the cooled receiver. 

Fig. 14.—Manufacture of Carbon Disulphide by the action of Sulphur Vapour on Carbon.

The production of thiophen when acetylene interacts with sulphur vapour has already been mentioned (p. 258). That this product is not the result of a secondary reaction between acetylene and carbon disulphide follows from the fact that thiophen is only produced in quantity from these two reactants at a considerably higher temperature than that required when sulphur is used. Acetylene saturated -with carbon disulphide vapour and passed through an electrically heated tube containing broken porous pot, yields a condensate which at the optimum temperature of 700° C. contains about 10 per cent, by volume of thiophen and 10 per cent, of hydrocarbons.1... 

Carbonyl Sulphide or Carbon Oxysulphide, COS.—Carbonyl sulphide, discovered by Than,5 is formed synthetically when a mixture of sulphur vapour and carbon monoxide is passed through a hot tube. The action is reversible,... 

When sulphur vapour and air are passed over a red-hot mixture of... 

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