Phosphorus slow combustion

When yellow phosphorus burns in an excess of oxygen, the main product is phosphorus pentoxide—possibly mixed with a little red phosphorus. When a considerable quantity of air is passed over phosphorus, the slow combustion which... 

Such a reaction, however, is not generally regarded as an example of slow combustion. Slow combustion is usually facilitated by the presence of a solid phase which may be the combustible substance itself—as in the case of phosphorus—or even an inert substance, such as... 

Preparation by Chemical Processes.—Ozone is formed to some extent during the slow combustion of certain substances such as phosphorus. In the case of phosphorus the occurrence of the ozone appears to be connected with the phosphorescence because substances which, by their presence, inhibit the phosphorescence, also prevent the formation of ozone.4... 

From the foregoing data it is evident that these spectra are similar to those which proceed from the slow combustion of phosphorus (p. 124). 

Phosphorus Trioxide.—The formation of an oxide by the slow combustion of phosphorus had already been noticed in the eighteenth century,7 and the existence of such a compound was known to Lavoisier and Davy, while the conditions of formation and the composition were established by Dulong.8... 

The formation of this oxide by the decomposition of P406 has been described already (p. 129). By heating in a sealed evacuated tube the products of the slow combustion of phosphorus, a crystalline sublimate is obtained,2 which was shown by Thorpe and Tutton 3 to be a distinct new oxide, probably formed according to the equation... 

Phosphorous Acid, H3P03.—The production of an acid liquid by the slow combustion of phosphorus in the presence of water was observed by le Sage in 1777. The acid was prepared by Pelletier by drawing a slow current of air over phosphorus enclosed in fine tubes which dipped into water.7 The distinction between this acid and phosphoric acid was recognised in the early nineteenth century, as also was the fact that the slow combustion of phosphorus could yield a mixture of the two acids.8... 

Fix, with a pair of forceps, a small piece of solid phosphorus in a quill pen and write with it (t. . the phosphorus), upon a piece of paper. If the paper be taken into a dark room, the. writing will be plainly visible. This luminosity arises from the slow combustion of the phosphorus. 

Pore phosphorus is a colourless, or very pale, yellowish, transparent, or translucent solid, of the consistence of wax. Its sp. g. is 1-77. At 113° it melts, and at 572° it boils, distilling completely in close vessels. It has, in the solid form, neither taste nor smell but it gives off vapours in the air, which, undeigoing a slow combustion, have an odour of garlic and in solution it has an acrid disagreeable taste. Phosphorus is insoluble in water, soluble in alcohol, ether, oils, sulphuret of carbon, and chloride of phosphorus. From the latter liquids it is often deposited in octahedral and dodecahedral crystals. It is very poisonous, but is used in medicine in very small doses. 

This acid is formed, along with phosphoric acid, during the slow combustion of phosphorus in air. It is best obtained pure by acting on the sesquichloride of phosphoros, P, Cl, by water. P,CL-t-6HO=3HCl-t-P, 0, 3HO. The hydrocldoric acid is easily expelled by a gentle heat, and the aqueous solution of... 

White phosphorus has an autoignition temperature only shghtly above ambient, dispersed it will soon heat itself to that by the slow oxidation responsible for its glow. Red is not spontaneously combustible, however if it does catch fire white will be produced, so that the fire, once extinguished, may spontaneously re-ignite. Both can produce phosphine, among other products, by slow reaction with water. Sealed containers of damp phosphorus (white is often stored under water) may pressurise with highly toxic, pyrophoric, gas mixtures [1]. 

Phosphorus has many allotropes. It is most commonly encountered as white phosphorous, which contains tetrahedral P molecules (1). Other forms, that are quite stable thermodynamically but kinetically harder to make, contain polymeric networks with three-coordinate P. White phosphorous is highly reactive and toxic. It will combine directly with most elements, glows in air at room temperature as a result of slow oxidation, and combusts spontaneously at a temperature above 35°C. Arsenic can also form As4... 

Oxidation processes arc, as a general rule, greatly accelerated by a rise in temperature the first effect of the application of heat may be merely to initiate a slow oxidation which soon ceases on the removal of the source of heat but a higher temperature may cause so marked an increase m the rate of the chemical action that the heat produced suffices to maintain the temperature, and the oxidation or combustion will proceed unaided. This temperature at which the process of rapid combustion becomes independent of external supplies of heat is termed the ignition temperature of the substance (see p. 106). Phosphorus does not commence rapid combustion until a temperature of 60° C. is attained hydrogen will combine, albeit excessively slowly, with oxygen already at 180° C., but the reaction is not very appreciable below 400° C., and continuous inflammation does not occur until near... 

---