Sodium ammonium orthophosphates

The solutions which were allowed to interact were about 0-08 N in order to avoid inclusions in the precipitates. The latter were well washed, and allowed to stand in water for at least 24 hours. Silver orthophosphate was stable in the presence of the moderate amounts of acid produced by some of the reactions which were tried. If silver nitrate is poured into excess of disodium hydrogen phosphate the precipitate settles rapidly, but precipitation is incomplete. If di-sodium ammonium phosphate is poured into silver nitrate the precipitate settles rapidly and the solution remains nearly neutral, according to the equation... 

FIGURE 5.4 Water solubility of (a) sodium and (b) ammonium orthophosphates. 

The commercial production of orthophosphates and polyphosphates, particularly the sodium, ammonium and calcium salts, together with phosphoric acid, greatly exceeds that of aU other compounds of phosphorus. The lion s share of these is used by the fertiliser industry, but detergents, animal foodstuffs, metal treatments and human food products are also major consumers. 

Sodium, potassium or ammonium orthophosphate, acetate, perchlorate or citrate salts are commonly used for buffering the eluent and should be of the highest... 

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. 

Discussion. When a solution of an orthophosphate is treated with a large excess of ammonium molybdate solution in the presence of nitric acid at a temperature of 20-45 °C, a precipitate is obtained, which after washing is converted into ammonium molybdophosphate with the composition (NH4)3[P04,12Mo03]. This may be titrated with standard sodium hydroxide solution using phenolph-thalein as indicator, but the end point is rather poor due to the liberation of ammonia. If, however, the ammonium molybdate is replaced by a reagent containing sodium molybdate and quinoline, then quinoline molybdophosphate is precipitated which can be isolated and titrated with standard sodium hydroxide ... 

Some phosphates are simple orthophosphates, whereas others are condensed phosphates. Polymeric forms are also available these are complex condensed polyphosphates, all of which may be present in hydrogen, sodium, potassium, or even ammonium form. 

Eberlein and Kattner [194] described an automated method for the determination of orthophosphate and total dissolved phosphorus in the marine environment. Separate aliquots of filtered seawater samples were used for the determination orthophosphate and total dissolved phosphorus in the concentration range 0.01-5 xg/l phosphorus. The digestion mixture for total dissolved phosphorus consisted of sodium hydroxide (1.5 g), potassium peroxidisulfate (5 g) and boric acid (3 g) dissolved in doubly distilled water (100 ml). Seawater samples (50 ml) were mixed with the digestion reagent, heated under pressure at 115-120 °C for 2 h, cooled, and stored before determination in the autoanalyser system. For total phosphorus, extra ascorbic acid was added to the aerosol water of the autoanalyser manifold before the reagents used for the molybdenum blue reaction were added. For measurement of orthophosphate, a phosphate working reagent composed of sulfuric acid, ammonium molyb-... 

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. 

The orthophosphates.—Orthophosphoric acid forms three salts, normal or tertiary, secondary, and primary phosphates, according as all, two, or one of its hydrogen atoms is replaced by an equivalent radicle.26 The hydrogen atoms may be replaced by different radicles. Thus, the secondary acid salt—ammonium sodium hydrogen phosphate, also called microcosmic salt—is illustrated by the subjoined graphic formula along with the formulae for the acid and the primary, secondary, and tertiary sodium salts ... 

The zirconium phosphate, a-ZrP, behaves as an ion exchanger where both hydrogen ions of the orthophosphate groups are exchangeable with sodium, potassium, and ammonium in two stages [109], It has an exchange capacity of 6.64 mequiv/g [111],... 

Pyro- and metaphosphates give the ammonium molybdate test on warming for some time this is doubtless due to their initial conversion in solution into orthophosphates. The chief differences between ortho-, pyro- and metaphosphates are incorporated in the following table. The student should carry out all the tests. To study these reactions use freshly prepared solutions of sodium pyrophosphate and sodium metaphosphate. 

Chromous Orthophosphate, CrgfPO lj.HaO, is the abundant blue gelatinous precipitate obtained w hen ordinary sodium phosphate is added to chromous chloride solution. It is readily soluble in acids, and on exposure to air rapidly changes to the green chromic salt. It does not form double salts with ammonium phosphate. ... 

Aibrite MALP. See Aluminum orthophosphate Aibrite Monoammonium Phosphate Food Grade. See Ammonium phosphate Aibrite Monosodium Phosphate] Aibrite MSP Food Grade. See Sodium phosphate Aibrite N-Octyi Acid Phosphate. See 2-Ethylhexyl phosphate Aibrite Octyiphenyi Acid Phoshate. See Octyl phenyl acid phosphate Aibrite PA. See Phosphorous acid Aibrite PCk. See Phosphorus trichloride Aibrite Phenyi Acid Phosphate. See Phenyl acid phosphate... 

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