Metaphosphate nitrates

The monofluorophosphates can be prepared by neutralization of monofluorophosphoric acid (1). Sodium monofluorophosphate [7631 -97-2] is prepared commercially (57) by fusion of sodium fluoride and sodium metaphosphate, and the potassium monofluorophosphate [14104-28-0] can be prepared similarly. Insoluble monofluorophosphates can be readily prepared from reaction of nitrate or chloride solutions with sodium monofluorophosphate. Some salts are prepared by metathetical reactions between silver monofluorophosphate [66904-72-1] and metal chlorides. 

Uranyl hydroxides, 25 430 Uranyl metaphosphates, 25 433 Uranyl nitrate, 25 428 Uranyl perchlorate crystals, 25 429 Uranyl sulfate system, 25 429 Urban air quality, 17 814—815 Urea(s), 8 206-207... 

Elemental composition P 38.73%, H 1.26%, O 60.01%. The compound may be identified by physical properties alone. It may be distinguished from ortho and pyrophosphates by its reaction with a neutral silver nitrate solution. Metaphosphate forms a white crystalline precipitate with AgNOs, while P04 produces a yellow precipitate and P20 yields a white gelatinous precipitate. Alternatively, metaphosphate solution acidified with acetic acid forms a white precipitate when treated with a solution of albumen. The other two phosphate ions do not respond to this test. A cold dilute aqueous solution may be analyzed for HPO3 by ion chromatography using a styrene divinylbenzene-based low-capacity anion-exchange resin. 

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. 

Pour a few drops of silver nitrate into a sodium metaphosphate solution. Note the colour of the precipitate. See how it reacts with dilute nitric acid. Write the equations of the reactions. In what medium can silver metaphosphate be precipitated ... 

Silver nitrate Metaphosphates, P03 White precipitate soluble in dilute nitric acid, dilute ammonia solution, and dilute acetic acid... 

Dimetaphosphates of copper, manganese, cobalt and zinc are said to be formed when an oxide or nitrate of these metals is heated with an excess of phosphoric acid between 316° and 400° C.2 The zinc salt had the formula ZnP208.4H20, and when treated with alkali sulphides gave the alkali salts K2P206.2H20, etc. Other authorities, however, have adduced reason for supposing that these salts are tri- or tetra-metaphosphates.4... 

Sodium metaphosphate, NaPOs.—The metaphosphate is prepared by the interaction of sodium nitrate and phosphoric acid at 330° C.20 It is a white, vitreous mass, almost insoluble in water, and melting21 at 617 2° C. It is sometimes called Maddrell s salt, after its discoverer.22 The semihydrate, NaP03, H20, is formed by heating sodium ammonium hydrogen phosphate at 160° to 170° C., and subsequently raising the temperature to 320° C.23 Tammann24 has proved the existence... 

Cupric metaphosphate, Cu(P03)2.—The metaphosphate is formed by evaporating to dryness an aqueous solution of cupric nitrate and ortho-phosphoric acid, and heating the residue at 816° C.10 The tetrahydrate is prepared by precipitating with alcohol a solution of cupric sulphate and sodium metaphosphate.11... 

Silver hypophosphate, Ag4P206.—Silver nitrate gives with sodium hypophosphate, Na4P206, a white precipitate of silver hypophosphate. It is also produced in crystalline form by boiling a solution of silver nitrate in nitric acid with phosphorus. Heat decomposes it into silver metaphosphate and metallic silver 3... 

Silver pyrophosphate, Ag4P207.—Precipitation of sodium pyrophosphate with silver nitrate yields the pyrophosphate in the form of a white powder, fusible at red heat. Secondary sodium orthophosphate converts it into silver orthophosphate. A double salt of the formula NaAg3P207 is also known. On heating, its colour changes from white to yellow, a phenomenon which has been attributed to decomposition into sodium metaphosphate and silver orthophosphate, but which is considered by Balareff 4 to have probably a physical origin. 

Silver metaphosphate, AgP03.—With a concentrated solution of sodium metaphosphate silver nitrate gives a white precipitate of the semihydrate, AgP03, H20.6 Other metaphosphate have been described.6... 

Nutrients are sources of N and P such as ammonia, nitrites, nitrates, orthophosphates, metaphosphates, and polyphosphates. They are present in fertilizers and are formed during biodegradation of organic matter in wastewater discharges or dead organic matter. 

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