Red-phosphorus sentence example
Orthophosphoric acid, H3P04, a tribasic acid, is obtained by boiling a solution of the pentoxide in water; by oxidizing, red phosphorus with nitric acid, or yellow phosphorus under the surface of water by bromine or iodine; and also by decomposing a mineral phosphate with sulphuric acid.
Numerous hydrides are known; heated with red phosphorus and hydriodic acid the hydrocarbon yields mixtures of hydrides of composition C10H10 to C10H20.
On oxidation it gives triphenylcarbinol, (C 6 H 5) 3 C OH, and reduction with hydriodic acid and red phosphorus gives benzene and toluene.
It decomposes when heated, hydrogen and red phosphorus being formed.
It slowly reacts with cold water to form phosphorous acid; but with hot water it is energetically decomposed, giving much red phosphorus or the suboxide being formed with an explosive evolution of spontaneously inflammable phosphoretted hydrogen; phosphoric acid is also formed.Advertisement
Phosphorus trichloride or phosphorous chloride, PC13, discovered by Gay-Lussac and Thenard in 1808, is obtained by passing a slow current of chlorine over heated red phosphorus or through a solution of ordinary phosphorus in carbon disulphide (purifying in the latter case by fractional distillation).
Water gives hydrochloric and phosphorous acids, with separation of red phosphorus if the water be hot.
The first is prepared by heating red phosphorus with finely powdered sulphur in a tube sealed at one end and filled with carbon dioxide.
The second, P4S7, is obtained by heating a mixture of red phosphorus and sulphur in the proportions given by P4S7+5% P4S3, and crystallizing from carbon disulphide in which P 4 S 3 is readily soluble.
Thus the conversion of yellow into red phosphorus evolves about one-sixth of the heat of combustion of the latter in oxygen, and so the knowledge of which variety of phosphorus has been employed is of essential importance in the thermochemistry of that element.Advertisement