Solubility magnesium ammonium phosphate

Magnesium nitrate reagent or magnesia mixture White crystalline precipitate of magnesium ammonium phosphate soluble in acetic acid and mineral acids practically insoluble in 2.5% ammonia solution... 

The presence of sparingly soluble components in human urine, such as calcium oxalate, calcium phosphate, magnesium ammonium phosphate, uric acid and l-cystine. Kidney stones are composed mainly of these compounds. 

For a precipitate used in gravimetric analysis magnesium ammonium phosphate has a rather high solubility (0.1 g dm 3 in water at 20°C). Hence solution volumes should be kept as low as possible and the precipitate must be filtered from cold solution. Furthermore, the solution composition must be carefully controlled to ensure the maintenance of conditions of... 

Write a balanced dissolution equation and solubility product expression for magnesium ammonium phosphate, MgNH4P04. 

Magnesium Ammonium Phosphate. MgNH(POr. white precipitate. K,t, 2.5 x 0 1 -. by reaction of soluble salt solution and sodium phosphate in the presence of excess ammonium hydroxide, upon igniting yields magnesium pyrophosphate. MgyPsOz. while solid. 

Self-Test 11.13B The solubility product of magnesium ammonium phosphate, MgNH4P04, is 2.5 X 10 l3. Estimate the molar solubility of the salt, which forms Mg24", NH41, and P043- ions in water. 

Indirect determinations of several types can be carried out. Sulfate has been determined by adding an excess of standard barium(II) solution and back-titrating the excess. By titrating the cations in moderately soluble precipitates, other ions can be determined indirectly. Thus sodium has been determined by titration of zinc in sodium zinc uranyl acetate, and phosphate by determination of magnesium in magnesium ammonium phosphate. Quantitative formation of tetracyano nickel-ate(II) has been used for the indirect determination of cyanide. ... 

Leach-Resistant Chemicals. Insoluble Complexes. Leach-resistant fire retardants can be formed by reacting soluble salts with metal salts to form insoluble, metallic salt complexes. Sodium silicate reacted with calcium chloride formed an insoluble, hydrated calcium silicate (95). Application of a 20% diammonium phosphate solution, followed by a 20% magnesium sulfate solution, has been proposed as a ready-to-use treatment for wood roofs (96). This combination forms an insoluble magnesium ammonium phosphate and is recommended for roofs that are 5 years old or older. Test results indicate that this treatment provides increased flame-spread protection. 

Magnesium ammonium phosphate has the formula MgNH4P04 6H20. It is only slightly soluble in water (its Ksp is 2.3 X 10 ). Write a chemical equation and the corresponding equilibrium law for the dissolution of this compound in water. 

The majority of kidney stones found in the western world are composed of one or more of the following substances (1) calcium oxalate with or without phosphate (frequency 67%), magnesium ammonium phosphate (12%) (2) calcium phosphate (8%) (3) urate (8%) (4) cystine (1% to 2%) and (5) complex mixtures of the above (2% to 3%). These poorly soluble substances crystallize within an organic matrix, the nature of which is not well understood. 

In some cases a compound contains more than two kinds of ions. Dissolution of the slightly soluble compound magnesium ammonium phosphate, MgNH PO, in water and its solubility product expression are represented as... 

These are generally made up of metabolic products present in the glomerular filtrate at levels close to their maximum solubility limit. Variation of the pH and composition of the urine or obstruction to urine flow may result in precipitation of substances in the kidney and contribute to calculi formation. Urinary calculi may be composed of calcium-containing stones such as calcium oxalate or calcium phosphate, both with and without magnesium ammonium phosphate, and stones containing either cystine, xanthine, or uric acid (21). The mucoprotein core around which the mineral salts precipitate account for 60% of the composition of the stone. 

The metal ammonium phosphates are a group of compounds of low solubility consisting of a divalent metal, ammonium, and phosphate ions with 0, 1, 3, or 6 moles of water of crystallization (2). Magnesium ammonium phosphate, the best known compound of the series, exists in two hydrated forms—i.e., with either 1 or 6 moles of water. 

The conditional solubility product of magnesium ammonium phosphate, struvite (MgNH4P04[s)) illustrates a situation where more than one of the dissolving species is affected by solution pH. These species are the ammonium ion NH4+) and the phosphate ion (P04 ). Because an increase in pH will decrease the ammonium ion concentration and increase the phosphate ion concentration, it follows that there should be a pH value where the solubility of MgNH4p04(s) is a minimum, that is, the pH where the product [Mg +][NH4 ][P04 ] is a minimum. Where is this point ... 

Fig. 6-19. Conditional solubility product, Ps = Ct.m3 Ct.nh, Ct.po, for magnesium ammonium phosphate at 25 C.

Magnesium oxide forms precipitates with fluorine in the reactor, which may blind the filter cloth therefore, high MgO content is considered undesirable. When phosphoric acid is used to produce ammonium phosphates or polyphosphates, water-insoluble (but citrate-soluble) magnesium ammonium phosphate compounds may be formed, These compounds form troublesome impurities in liquid fertilizers. 

The colored ion of highly colloidal dyestuffs, as is well known, is adsorbed by very many substances so that the assumptions underlying the above equations are not at all strained. The wider precipitation zones of dyestuffs having a lesser colloidal character may be explained on the basis of greater solubility of the dye salt formed, and also on the lessened adsorption. We have here relations similar to the precipitation of insoluble inorganic salts, such as barium sulfate, magnesium ammonium phosphate, etc., where sol formation is difficult because large particles form so easily. 

If phosphate has been detected previously (e.g. in the cation analysis), a qualitative test for arsenate may be made as follows. Pour 1 ml AgN03 solution, to which 2 drops of dilute acetic acid have been added, over the white precipitate. A brownish-red colouration of the precipitate confirms the presence of arsenate. The acetic acid is added to increase the solubility of the magnesium salt and thus facilitate the conversion of magnesium ammonium arsenate to the characteristic silver arsenate. 

These ammonium phosphates are made by reacting ammonium nitrate with phosphoric acid. The resulting compounds are very soluble in water. During formation of ceramics, ammonia is released and phosphate reacts with metal cations such as magnesium and forms the CBPC. Because of the evolution of ammonia, it is used for outdoor applications such as road repair material and hardly any indoor applications have been found for these products. 

Nitrogen sources include proteins, such as casein, zein, lactalbumin protein hydrolyzates such proteoses, peptones, peptides, and commercially available materials, such as N-Z Amine which is understood to be a casein hydrolyzate also corn steep liquor, soybean meal, gluten, cottonseed meal, fish meal, meat extracts, stick liquor, liver cake, yeast extracts and distillers solubles amino acids, urea, ammonium and nitrate salts. Such inorganic elements as sodium, potassium, calcium and magnesium and chlorides, sulfates, phosphates and combinations of these anions and cations in the form of mineral salts may be advantageously used in the fermentation. 

The solubility of the precipitates encountered in quantitative analysis increases with rise of temperature. With some substances the influence of temperature is small, but with others it is quite appreciable. Thus the solubility of silver chloride at 10 and 100 °C is 1.72 and 21.1mgL 1 respectively, whilst that of barium sulphate at these two temperatures is 2.2 and 3.9 mg L 1 respectively. In many instances, the common ion effect reduces the solubility to so.small a value that the temperature effect, which is otherwise appreciable, becomes very small. Wherever possible it is advantageous to filter while the solution is hot the rate of filtration is increased, as is also the solubility of foreign substances, thus rendering their removal from the precipitate more complete. The double phosphates of ammonium with magnesium, manganese or zinc, as well as lead sulphate and silver chloride, are usually filtered at the laboratory temperature to avoid solubility losses. 

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