White phosphorus acid with

White phosphorus reacts with oxygen to produce an oxide (P2O5). This oxide then reacts with any water that is around to form phosphoric acid. The phosphorus-phosphorus bonds of P4 are weak compared with the stronger phosphorus-oxygen bonds of P2O5 in other words, the oxide is thermodynamically much more stable than white phosphorus, and this drives the reaction to such an extent that white phosphorus spontaneously combusts in air. 

Phosphorus smokes are generated by a variety of munitions. Some of these munitions (such as the MA25 155-mm round) may, on explosion, distribute particles of incompletely oxidized white phosphorus. Contact with these particles can cause local burns, and systemic toxicity may occur if therapy is not administered. Therapy consists of topical use of a bicarbonate solution to neutralize phosphoric acids and mechanical removal and debridement of particles. A Wood s lamp in a darkened room may help to identify remaining luminescent particles. 

Phosphorus forms both pyramidal trihalides and trigonal bipyramidal penta-halides with all four halogens. Taking the chlorides as representative, the reaction of white phosphorus, P4, with a limited amount of chlorine gas yields the colorless liquid PCI3, whereas if an excess of chlorine is used, the off-white solid PCI5 is formed. The trihalide is hydrolyzed to phosphorus acid, whereas the pentahalide... 

Bromine (7 ml) is added dropwise to a mixture of white sand (14 g) and red phosphorus (3 g, dried at 165° under vacuum) moistened with 5 ml of deuterium oxide. The apparatus is fitted with an exit tube to allow the liberated deuteriobromic acid to pass through two U-tubes and into a receiving flask. The first trap contains glass beads and is cooled in an ice-salt slurry. The second contains glass beads and red phosphorus moistened with deuterium oxide. The deuterium bromide gas is collected in the appropriate solvent at ice bath temperature. A small amount of phosphorus pentoxide should be added to remove any deuterium oxide if anhydrous reagent is required. 

Salts of aminoalkylidenephosphonic acids form perhydrates with hydrogen peroxide which are durable under storage [137], Another method exists for the preparation of aminoalkylidene phosphorus compounds by conversion of white phosphorus with N-hydroxymethyldialkylamine [138-140], as shown in Eq. (80). 

Carbon-phosphorus double bonds are also formed in addition reactions of tris(trimethylsilyl)phosphine 1692 (which can be readily prepared from white phosphorus, sodium, and TCS 14 [13a,b,c]) to give oxazohum fluorides 1691 which then give the azaphospholes 1694, via 1693 [3, 14]. On addition of 1692 to 1695, the diazaphosphole 1696 [3, 15] is prepared, whereas l,3-azaphospholo[l,2a]pyridines 1698 [16] are formed from 1692 and 1697, and 1,3-thiaphospholes 1700 are formed from the dithiohum fluorides 1699 [17]. l,3-Benzodiphospholyl anions 1703 are generated by reaction of acid chlorides with the dihthium salts 1701, via 1702 [18] (Scheme 11.3). 

White phosphorus reacts violently with sulphuric acid when it is hot. 

M. Watt and J. Evans, Linking development and determinacy with organic acid efflux from proteoid roots of white lupin grown with low phosphorus and ambient or elevated atmospheric COi concentration. Plant Pltywlol. 120 705 (1999). 

The only element that was discovered in body fluids (urine). This is plausible, as P plays a main role in all life processes. It is one of the five elements that make up DNA (besides C, H, N, and 0 evolution did not require anything else to code all life). The P-O-P bond, phosphoric acid anhydride, is the universal energy currency in cells. The skeletons of mammals consists of Ca phosphate (hydroxylapatite). The element is encountered in several allotropic modifications white phosphorus (soft, pyrophoric P4, very toxic), red phosphorus (nontoxic, used to make the striking surface of matchboxes), black phosphorus (formed under high pressures). Phosphates are indispensable as fertilizer, but less desirable in washing agents as the waste water is too concentrated with this substance (eutrophication). It has a rich chemistry, is the basis for powerful insecticides, but also for warfare agents. A versatile element. 

White phosphorus ignites in contact with boiling sulfuric acid or its vapour [1], An explosion hazard exists at industrial scale under milder conditions [2], Even... 

Fundamentally, O-esters of N-hydroxy-2-thiopyridone are photo-lyzed in the presence of an excess of white phosphorus in a methylene chloride/carbon disulfide medium. On solvent removal, hydrolysis, and oxidation with hydrogen peroxide, good yields of phosphonic acids (Figure 2.10) bearing the carbon functionality of the parent acid are isolated. 

A solution of 10 ml of 10 N aqueous KOH diluted to 25 ml with absolute ethanol was added dropwise over a period of 30 min to a well-stirred mixture of 0.4 g-atom (12.4 g) of finely divided white phosphorus, 1.2 mol (85.2 g) of acrylamide, and 200 ml of absolute ethanol under a nitrogen atmosphere. The temperature was maintained at -5 to 0°C by a cooling bath. After stirring for an additional 45 min, the white solid generated was recovered by filtration. This solid was dissolved in 125 ml of hot glacial acetic acid, and the solution was cooled to room temperature. (Any unreacted white phosphorus could be removed at this point by decantation under a nitrogen atmosphere.) The solution was filtered through diatoma-ceous earth, diluted with 600 ml of absolute ethanol, and cooled at 5°C for 30 min. The resultant white solid was collected by filtration, washed with absolute ethanol, and dried to produce the pure tris(2-carbamoylethyl)phosphine oxide in 74% yield. 

In the second instance, two approaches seem to be worthy of special note. The synthetic utility of elemental phosphorus based on it acting as a radical trap appears to be quite valuable, but additional effort is required to determine the variability of the source of the organic free radicals. (Is there some other, more efficacious, source of organic free radicals that works better with this system than acylated iV-hydroxy-2-pyridones ) The other approach that appears ripe for development is the hydrolysis/elimination with "phosphorates" derived from the oxidative addition of white phosphorus to alkenes. We look forward to the continued development of such facile approaches toward the preparation of fundamental phosphonic acids. 

The method, described relatively early, for the preparation of phosphine using the reaction of hot concentrated alkalies, such as NaOH, KOH or Ca(OH)2, on white phosphorus can also be used for the laboratory preparation. This method also produces a steady stream of phosphine, which, however, may be contaminated by up to 90% hydrogen and traces of P2H4 >>3.8s.ioi-io6) phine formed from the thermal decomposition of phosphorous or hypophos-phorous acids or their salts is similarly contaminated with hydrogen. In cases where hydrogen interfers, the phosphine can be purified by condensation and distillation. 

Finally, in the recent patent literature, some further processes for the preparation of phosphine were described for example, the treatment of white phosphorus with steam in the presence of phosphoric acid at 275-285 °C. According to a British patent, phosphine is formed when white phosphorus, in aqueous acid, is brought into contact with mercury or zinc amalgam A Japanese patent recommends the treatment of a mixture of white phosphorus and granulated zinc with acids and a small amount of methanol for the preparation of highly pure phosphine. Other patents describe electrolytic processes. Finally, it is mentioned that phosphine is formed by the electrolysis of phosporous and hypophosphorous acid, especially at mercury or lead cathodes. ... 

White phosphorus also can be produced by a wet process using phosphoric acid, a process that was practiced historically in commercial production. In this method the starting material, phosphoric acid, usually is prepared in large vats by reacting phosphate rock with sulfuric acid ... 

Phosphorus acid is a powerful reducing agent. When treated with a cold solution of mercuric chloride, a white precipitate of mercurous chloride forms ... 

Phosphorus acid reacts with sdver nitrate in dilute solution yielding a white precipitate of sdver phosphite, AgsPOs, which reduces to metaUic silver. 

Phosphorus is available in two forms, white (or yellow) and red. White phosphorus appears to be molecular, with a formula of P,. It is a waxy solid with a melting point of 44°C, and ignites spontaneously on exposure to air. It must be kept cool and is usually stored under water. It is highly toxic in both the solid and vapor form and causes burns on contact with the skin. Its use in pyrotechnics is limited to incendiary and white smoke compositions. The white smoke consists of the combustion product, primarily phosphoric acid (H 3PO,). 

Ammonium metaphosphates.—The product obtained by H. N. Stokes6 by boiling monamidophosphoric acid, NHa.PO(OH)2, is either ammonium mono-metaphosphate, or a mixture of different metaphosphates—vide infra. G. Tam-mann prepared microscopic crystals of what he called ammonium /3-monometa-phosphate, NH4P08, by crystallization in the cold of a soln. of phosphorus pentoxide and glassy metaphosphoric acid with ammonium carbonate. A soln. of the purified salt gives a white precipitate with silver nitrate. The air-dried salt has the composition NH4P03.3,4H2O and it passes in a few weeks into the orthophosphate. 

The compounds may have either the formula H3PO4 (m.p., 40°) or 2H3P04-H20 (m.p., 30°). In a round-bottomed flask of suitable size, place 1 part of white phosphorus and 16 parts of nitric acid of sp. gr. 1.2 together with a few crystals of iodine as a catalyzer. Provide the flask with a reflux condenser, painting the cork with black asphalt paint to protect it from the action of the nitric acid. Heat until all of the phosphorus has dissolved then distill off most of the liquid and pour the residue into an open dish. Evaporate with several additions of concentrated nitric acid to oxidize all lower acids of phosphorus and finally concentrate in a platinum dish until the temperature of the solution reaches 150°. On cooling, if necessary with a freezing mixture, the liquid can be brought to crystallization. The crystals should be dried over phosphorus pentoxide... 

Fill the retort B with dry carbon dioxide, generated in F and dried by sulfuric acid in G, and then place in it 20 g. of white phosphorus, cut into small pieces under water and dried piece by piece on filter paper. Continue the current of carbon dioxide until the phosphorus is entirely dry, then add sufficient carbon disulfide to dissolve the phosphorus (about 20 cc.). Cool the retort in running water and add 34 g. of iodine gradually in small quantities and with thorough shaking after each addition. 

Owing to its powerful affinity for oxygon, phosphorus reduces the compounds of the noble metals, when placed in contact with their solutions, and quickly becomes covered with the reduced and precipitated metal. In contact with chlorine, bromine, and iodine, phosphorus inflames spontaneously, and without the aid of heat, producing respectively, chloride, bromide, and iodide of phosphorus. When heated in a copious supply of dry air, phosphorus hums with a brilliant white light, producing white fumes of anhydrous phoB-phoric acid, P04, which, when condensed, much resembles snow. 

There is a series of analogous cyclic thiuphosphoric acids with the formula (HS2P) thal may be prepared by the oxidation of red or white phosphorus with polysulfides under a variety of conditions. For example, the reaction of white phosphorus with a mixture of sulfur and hydrogen sulfide dissolved in triethylamine (which acts as a base) and chloroform opens the phosphorus cage to form the tectamerre cyclic anion ... 

White phosphorus reduction. White phosphorus, and indeed sodium or potassium thiocyanate, are fast reducers. Chloroauric acid is boiled under reflux with white phosphorus (6) dissolved in diethylether. Boiling is continued until the solution turns from a brownish shade to red—this usually takes about 5 mm. This method produces gold particles m the smaller size range (2-12 nm) Accurate production of the particle size range is not easy, and, since the procedure is potentially highly dangerous, it is not commonly used... 

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