Salts of Phosphoric Acids

Hydrolysis of Ortho- and Pyrophosphoric Acid Salts. Use a universal indicator to determine the pH of a solution of mono-, di-, and trisubstituted sodium salts of orthophosphoric acid, and also of di- and tetrasubstituted sodium salts of pyrophosphoric acid. Write the equations of the reactions and explain why a different medium is obtained when the given salts are dissolved in water. 

Calcium Salts of Orthophosphoric Acid. Pour a calcium chloride solution into three test tubes. Add ammonia and a sodium hydrogen phosphate solution to one of them, only a sodium hydrogen phosphate solution to the second one, and a sodium dihydrogen phosphate solution to the third one. What do you observe Write the equations of the reactions and explain how the medium affects the course of the process. 

Test how the prepared precipitates react with acetic or hydrochloric acids. Explain the observed phenomena. What is the composition of phosphorite, precipitate, superphosphate, and double superphosphate What are the conditions for their use in agriculture  

Thermal Decomposition of Orthophosphates. Roast several crystals of monosubstituted sodium orthophosphate on the lid of a crucible. Continue the decomposition reaction until it terminates (how can this be determined ). Cool the product of roasting, dissolve it in water, and determine the salt of what phosphoric acid is in the solution. Write the equation of the reaction. 

What products form when disubstituted sodium and ammonium-sodium orthophosphates are roasted What orthophosphates are used as fertilizers Compare the strength of the oxyacids of phosphorus, sulphur, and chlorine, and also of nitrogen and phosphorus. 

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A newer self-intumescent phosphoric acid salt has been introduced by Albright WHson as Amgard EDAP, mainly as an additive for polyolefins. It is a finely divided soHd, mp 250°C, having a reported phosphoms content of 63 wt % as H PO. It appears to be the ethylenediamine salt of phosphoric acid (1 1). Unlike ammonium polyphosphate, it does not require a char-forming synergist (62). 

Orthophosphate salts are generally prepared by the partial or total neutralization of orthophosphoric acid. Phase equiUbrium diagrams are particularly usehil in identifying conditions for the preparation of particular phosphate salts. The solution properties of orthophosphate salts of monovalent cations are distincdy different from those of the polyvalent cations, the latter exhibiting incongment solubiUty in most cases. The commercial phosphates include alkah metal, alkaline-earth, heavy metal, mixed metal, and ammonium salts of phosphoric acid. Sodium phosphates are the most important, followed by calcium, ammonium, and potassium salts. 

The sodium salt of phosphoric acid, sodium phosphate (NaH2P04), is weakly acidic, and is used with sodium bicarbonate to make baking powders. Other acids used in baking powder are fumaric acid and tartaric acid. 

There are some means for synthesis of defined primary or secondary esters. Monoester salts of phosphoric acid, for instance, are prepared by addition of alcohol or ethoxylated alcohol, alkali fluoride, and pyrophosphoryl chloride (C12P0)20 in a molar ratio of 0.9-1.5 0.05-1 1.0 at -50 to +10°C and hydrolysis of the Cl-containing intermediates with base. Thus, 32.3 g (C12P0)20 was treated at -50°C with 23.9 g lauryl alcohol in the presence of 0.7 g KF and the mixture was slowly warmed to room temperature and hydrolyzed with H20 and 40% NaOH to give 83% sodium monolauryl phosphate. The monoester salts showed comparable or better washing and foaming efficiency than a commercial product [12]. 

Treating petroleum oils with 3-5% calcium alkyl salicylate and 0.5-3% triethanolamine salts of phosphoric acid esters and ethoxylated dodecyl alcohol increases oxidation-thermal stability at 180-200°C in the manufacture of oil for metal parts quenching. The agent provides also short-term anticorrosion protection of the hardened articles [261]. Phosphoric acid salt alkyl esters are used in anticorrosives and aqueous dispersions in waterborne polyester coatings for metals [244]. 

Sensitive dienol ether functionality in the diene carboxylate was shown to be compatible with the conditions of the aqueous Diels-Alder reaction (Eq. 12.26).84 The dienes in the Diels-Alder reactions can also bear other water-solubilizing groups such as the sodium salt of phosphoric acid and dienyl ammonium chloride (Eq. 12.27).85 The hydrophilic acid functionality can also be located at the dienophile.86... 

E) Salts of phosphoric acid can be formed by replacing one, two, or three of the hydrogen ions. For example, KH2PO4, sodium dihydrogen phosphate, can be formed by reacting one mole of phosphoric acid with one mole of potassium hydroxide. 

USEPA (2000) Phosphorous acid and its ammonium, sodium, and potassium salts (076002) Mono- and Di-potassium Salts of Phosphorous Acid (076416) Fact Sheet http //www.epa.gov/oppbppdl / biopesticides/ingredients/factsheets/ factsheeL076002.htm (last accessed... 

Ammonium Salts of Phosphoric Acid. Put several crystals of one of the ammonium salts of phosphoric acid on the lid of a crucible and heat them. Identify the substance remaining on the crucible lid after heating. Write the equation of the reaction. 

Ethylene is catalytically hydrated to ethyl alcohol by steam at 100°— 300°, the catalysts being salts of phosphoric acid. (E.P., 423877.)... 

The salts of phosphoric acid are very widely distributed and, as J. B. J. D. Bous-singault4 noticed, most of the naturally occurring phosphates are salts of ortho-phosphoric acid. This, however, does not necessarily mean that they were not formed at a high temp. W. B. Phillips has compiled a list of 141 minerals with the equivalent of over one per cent, of phosphoric acid. In the appended list, the... 

Argentum salt of phosphoric acid dibenzyl ester... 

Although the treatment of a phosphorodichloridate with the tri-n-butylammonium salt of phosphoric acid seems a plausible route to nucleoside diphosphates, this has recently been shown instead to be a means of preparing the triphosphate.8 Probably the most reliable method for preparing diphosphates is that described by Poulter,9 in which the tetra-n-butylammonium salt of a nucleophilic phosphorus component, for example, pyrophosphate is reacted with a nucleoside 5 -tosylate in acetonitrile (Figure 9.2). 

The most important of the double salts of phosphoric acid with ammonium and the alkali-metals is sodium ammonium hydrogen phosphate or microcosmic salt, NaNH4HP04,4H20, a constituent of putrefying urine, and also present in guano under the name stercorite.17 It can be prepared by the interaction of secondary sodium phosphate and ammonium chloride, or that of secondary ammonium phosphate and sodium chloride. It forms colourless columnar crystals belonging... 

Primary and secondary amines also undergo reductive methylation in >80% yield on reaction with aqueous foimaldehyde and a salt of phosphorous acid (NaH.PO,) in dioxanc. ... 

Phosphorus compounds make up a vast quantity of chemicals used by industry and consumers throughout the world. Of the many phosphorus compounds that exist, phosphates (the salts of phosphoric acids) are the ones most freqently used in textile processing. 

The classification of eluents into the two categories mentioned above is only meaningful and necessary in the framework of conductivity detection with its different application requirements. Eluent selection is much easier for applications using spectrophoto-metric or amperometric detectors, respectively. In photometric detection, both the photometric properties of the eluent ions and their chemical properties have to be taken into account nevertheless, a large number of eluents are available. The alkali salts of phosphoric acid, sulfuric acid, and perchloric acid have proved successful, because they all feature a good UV transmittance. In the field of amperometric detection, the choice... 

Nicotinamide Nucleotides.— The reaction between phosphorothioates and disilver salts of phosphoric acids has been used to synthesize FAD, UDPGlc, and UDPGal in high yield. An advantage of this method is that by-products such as symmetrical pyrophosphates are not formed. 

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