Combustion phosphorus

In fact, the estimation of flammability on the basis of elementary composition is even more dubious, considering that some incombustible elements such as halogens have a much higher suppressing effect on the flammability than other incombustible ones. Moreover, phosphoric esters containing combustible phosphorus are actually used as flame-retardant agents. 

A third screening smoke-type is white phosphoms [7723-14-0] (WP), P (see Phosphorus and THE phosphides), which reacts spontaneously with air and water vapor to produce a dense cloud of phosphoms pentoxide [1314-56-3]. An effective screen is obtained as the P2O5 hydrolyzes to form droplets of dilute phosphoric acid aerosol. WP produces smoke in great quantity, but it has certain disadvantages. Because WP has such a high heat of combustion, the smoke it produces from bulk-filled munitions has a tendency to rise in pillarlike mass. This behavior too often nullifies the screening effect, particularly in stiU air. Also, WP is very brittle, and the exploding munitions in which it is used break it into very small particles that bum rapidly. 

Fire Hazards - Flash Point (deg. F) 82 - 105 CC (solutions only pure liquid difficult to burn) Flammable Limits in Air (%) Not pertinent Fire Extinguishing Agents (for solutions) Foam, dry chemical, or carbon dioxide Fire Extinguishing Agents Not to be Used Water may be ineffective Special Hazards of Combustion Products Oxides of sulfur and phosphorus are generated in fires Behavior in Fire Not pertinent Igrution Temperature Not pertinent Electrical Hazard Data not available Burning Rate (for solutions) 4 mm/min. 

Dispersants To keep insoluble combustion and oxidation products in suspension and dispersed Salts of phenolic derivatives polymers containing barium, sulphur and phosphorus calcium or barium soaps of petroleum sulphonic acids... 

Phosphorus from organophosphorus compounds, which are combusted to give mainly orthophosphate, can be absorbed by either sulphuric acid or nitric acid and readily determined spectrophotometrically either by the molybdenum blue method or as the phosphovanadomolybdate (Section 17.39). 

Ion chromatography has been successfully applied to the quantitative analysis of ions in many diverse types of industrial and environmental samples. The technique has also been valuable for microelemental analysis, e.g. for the determination of sulphur, chlorine, bromine, phosphorus and iodine as heteroatoms in solid samples. Combustion in a Schoniger oxygen flask (Section 3.31 )is a widely used method of degrading such samples, the products of combustion being absorbed in solution as anionic or cationic forms, and the solution then directly injected into the ion chromatograph. 

The substance indicated by the same symbol in two or more equations is in exactly the same state in the reactions represented by those equations. In particular, the different allotropic modifications of a solid element (e.g., charcoal, graphite, diamond or yellow and red phosphorus) have different heats of combustion, and the particular form used must be specified in every case. 

The Ru(II)-BINAP complex,2 [Et2NH2]+[Ru2Cl5(BINAP)2]-,3 is prepared as a toluene solvate in nearly pure form by this procedure. Typical crystallized product shows no other signals in the phosphorus NMR and gives a good combustion analysis. The material is quite stable and can be routinely handled in air. Storage under nitrogen will extend its shelf life, however. 

LIF has been used in a multitude of studies to measure the concentrations of some important radicals, most frequently of OH, CH, and NO. While OH is an important contributor to the fuel degradation and oxidation pathways and an indicator of hot areas in flames, CH has often been used to trace the flame front location, whereas the direct investigation of NO formation is of importance with regard to NO, being a regulated air toxic. Species including other elements, such as sulfur, phosphorus, alkali, etc., can be detected by LIF in combustion systems, and often, an indication of their presence may already be a useful result, even if quantification is not possible. 

A major feature of the polyphosphazene skeleton is its ability to resist fire and combustion due to the inorganic elements constitutive of its structure [44,387, 388,459,460]. Moreover, the action of skeletal nitrogen and phosphorus atoms can be enhanced by inserting additional inorganic elements (F, Cl, Br, J, B, metals, etc.) in the substituent groups [459,460]. 

High-purity H3 PO4 is obtained using a more expensive redox process that starts from the pure element. Controlled combustion of white phosphorus gives phosphorus(V) oxide, P4 Oio, whose structure is shown in Figure 21-11 P4 -F 5 O2 P4 Oio Addition of water to P4 Oio generates highly pure phosphoric acid ... 

The simultaneous analysis of orthophosphate, glycerol phosphates, and inositol phosphates has been achieved by spectrophotometric analysis of the molybdovanadate complexes. Also, a sensitive and selective chemiluminescent molecular emission method for the estimation of phosphorus and sulphur is described, which is based on passing solutions into a cool, reducing, nitrogen-hydrogen diffusion flame. For organic compounds it was usually necessary to prepare test solutions by an oxygen-flask combustion technique. 

An air/nitric acid/phosphorus mixture in the gaseous state combusts spontaneously. The same is true for hot phosphorus or in the molten state when nitrogen oxides are present. 

The mixtures of sodium with phosphorus, phosphoryl trichloride or with phosphorus pentachloride combust spontaneously and/or detonate. There is an instantaneous ignition when powdered aluminium is mixed with trichloride or phosphorus pentachloride. 

The phosphorus hydride which is formed combusts in contact with the oxygen that... 

Trichloride and phosphorus pentachloride combust in contact with fluorine. 

Trichloride and pentachloride phosphorus combust when they are mixed with hydroxyiamine. 

The white phosphorus/sulphur mixture either combusts or detonates when it is heated. It forms diphosphorus pentasulphide. Red phosphorus reacts with more difficulty there is a need for an ignition flame and as a result of which the mixture combusts violently. This reaction is thought to lead to tetraphosphorus trisulphide. 

Chlorine has caused numerous accidents with metals. Beryllium becomes incandescent if it is heated in the presence of chlorine. Sodium, aluminium, aluminium/titanium alloy, magnesium (especially if water traces are present) combust in contact with chlorine, if they are in the form of powder. There was an explosion reported with molten aluminium and liquid chlorine. The same is true for boron (when it is heated to 400°C), active carbon and silicon. With white phosphorus there is a detonation even at -34°C (liquid chlorine). 

Boron trifluoride, sulphur and disulphur dichlorides, phosphorus trichloride in the liquid state cause potassium to combust. The same is true for phosphorus pentachloride in the solid state. In the latter case the same accident happened with gaseous halide. The same is also true for the bromide analogues of these compounds. 

Sulphur as well as phosphorus gives highly violent reactions when they are heated with potassium. With carbon disulphide, potassium creates a mixture, which detonates on impact. The same happens by heating. With sulphur dioxide, potassium in the molten state combusts. Finally, the potassium/sulphuric acid mixture gives rise to detonations. 

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