Monosodium phosphate

A typical process for the preparation of a poly(methyl methacrylate) suspension polymer involves charging a mixture of 24.64 parts of methyl methacrylate and 0.25 parts of benzoyl peroxide to a rapidly stirred, 30°C solution of 0.42 parts of disodium phosphate, 0.02 parts of monosodium phosphate, and 0.74 parts of Cyanomer A-370 (polyacrylamide resin) in 73.93 parts of distilled water. The reaction mixture is heated under nitrogen to 75°C and is maintained at this temperature for three hours. After being cooled to room temperature, the polymer beads are isolated by filtration, washed, and dried (69). 

Uses. The principal use of monosodium phosphate is as a water-soluble soHd acid and pH buffer, primarily in acid-type cleaners. The double salt, NaH2P04 H PO, referred to as hemisodium orthophosphate or sodium hemiphosphate, is often generated in situ from monosodium phosphate and phosphoric acid in these types of formulations. Mixtures of mono- and disodium phosphates are used in textile processing, food manufacture, and other industries to control pH at 4—9. Monosodium phosphate is also used in boiler-water treatment, as a precipitant for polyvalent metal ions, and as an animal-feed supplement. 

Several crystalline condensed phosphates may also be formed by the dehydration of monosodium phosphate (MSP). Maddrell s salt exists as Form 11 (high temperature MaddreU, NaPO -ll, insoluble metaphosphate-11) and Form 111 (low temperature MaddreU, NaPO -lll, insoluble metaphosphate-111). Both forms are highly polymerized and difficult (slow) to dissolve in water. Mixtures of the two forms are marketed as a dental abrasive for toothpaste formulations containing soluble fluoride. Maddrell s salt is also used with disodium phosphate as a cheese emulsifying aid. 

Figure 5 shows the phosphate—pH relationship recommended to control boiler corrosion. Different forms of phosphate consume or add caustic as the phosphate shifts to the proper form. For example, addition of monosodium phosphate consumes caustic as it reacts with caustic to form disodium phosphate in the boiler water according to the following reaction ... 

Properties. Cyanamide [420-04-2] also called carbamodiimide or carbamic acid nitrile, crystallises from a variety of solvents as somewhat unstable, colorless, orthorhombic, dehquescent crystals (2). Dimerization is prevented by traces of acidic stabilizers such as monosodium phosphate and by storage at low temperature. 

For production of commercial 50% solution and for recovery of crystalline cyanamide, this process is modified to improve purity and concentration. Calcium and iron may be removed by ion-exchange treatment. The commercial 50% solution is stabilized at pH 4.5—5.0 with 2% monosodium phosphate and contains less than 1.5% dicyandiamide and 0.2% urea. Such solutions are expected to show less than 1% change ia cyanamide content per month of storage below 10°C. It is advisable, however, to adjust the pH periodically duriag extended storage. Organic esters may be used iastead for improved stabihty (23). 

Inorganic compounds Monosodium phosphate mixed with boric acid and ethyl carbonate, disodium phosphate sodium aliiminate, bentonite and other solids Distillation instant coffee boiler feedwater sugar extraction... 

Chemical Designations - Synonyms Sodium phosphate is generic term and includes the following (1) monosodium phosphate (MSP sodium phospWe, monobasic), (2) disodium phosphate (DSP sodium phosphate dibasic), (3) trisodium phosphate (TSP sodium phosphate, tribasic), (4) sodium acid pyrophosphate (ASPP SAPP disodium pyrophosphate (TSPP), (6) sodium metaphosphate (insoluble sodium metaphosphate), (7) sodium trimetaphosphate, and (9) sodium tripolyphosphate (STPP TPP) Chemical Formula (1) NaHjPO (2) Na HPO (3) NajPO (4) Na H P O, (5) Na P O, (6) (NaPOj) (7) (NaP03)3 (8) (NaP03) NaO (9) Na,P30,o. 

Ci0H12N4O8P- Na+ 8 H20 Inosine 5 -(monosodium phosphate), octahydrate NAINPH10 31 370... 

Monosodium L-glutamate (MSG), 12 49 Monosodium phosphate (MSP), 18 833 manufacture of, 18 853, 857-858 thermal dehydration of, 18 846 Monostatic optical arrangement, 23 139 Monosubstituted boranes, 13 635-636 Monoterpenoid alcohols, 24 500-528 bicyclic, 24 527-528 monocyclic, 24 509-527 Monoterpenoid aldehydes, 24 529-536 Monoterpenoid ethers, 24 528-529 Monoterpenoid hydrocarbons,... 

E 339 Sodium phosphates (i) Monosodium phosphate (ii) Disodium phosphate (iii) Trisodium phosphate... 

Monoammonium glutamate Monocalcium citrate Monocalcium phosphate Monomagnesium phosphate Monopotassium citrate Monopotassium glutamate Monopotassium phosphate Monosodium citrate Monosodium glutamate Monosodium phosphate Montan acid esters Na, K and Ca salts of fatty acids Natamycin (pimaricin)... 

A second neutralization is carried out with soda ash to a pH level of about 4. Special heating, agitation, and retention are next employed to adequately condition the slurry so that filtration separation of the contaminants can be accomplished. The remaining solution is sufficiently pure for the production of monosodium phosphate, which can be further converted into other compounds such as sodium metaphosphate, disodium phosphate, and trisodium phosphate. A typical process flow diagram is shown in Figure 6. Wastewater effluents from these processes originate from leaks and spills, hltration backwashes, and gas scrubber wastewaters. 

In a laboratory hood, equip a 500-ml three-necked flask with a sealed stirrer and motor, condenser, thermometer, and an addition funnel. Add 150 ml of a 1% solution of sodium poly (methacrylate) in water and a buffer solution of 0.85 g of disodium phosphate and 0.05 g of monosodium phosphate in 5 ml of water. 

High boiler-water alkalinity tends to increase carryover, particularly in the presence of an appreciable quantity of suspended matter. This effect may be corrected by various methods, dependent on the cause of the high alkalinity. For example, if trisodium phosphate is being added to the boiler water, a less alkaline phosphate, such as disodium or monosodium phosphate will help in reducing alkalinity. 

The various sodium phosphates include monosodium phosphate (NaH2P04), disodium phosphate (NajHPO, and trisodium phosphate (4Na3P04 NaOH 48H20). 

To produce sodium tripolyphosphate, a definite temperature control is necessary. When monosodium phosphate and disodium phosphate in correct proportions, or equivalent mixtures of other phosphates, are heated for a substantial time between 300 and 500°C and slowly cooled, the product is practically all in the form of the tripolyphosphate. 

These salts are employed in water treatment, baking powder (monosodium phosphate), fireproofing, detergents, cleaners, and photography. 

Test solutions of monosodium phosphate, NaH2PC>4, disodium phosphate, Na2HP04, and trisodium phosphate, Na3PC>4, with litmus paper. See pages 116-117. Explain how a compound can be an acid salt and react alkaline to litmus. 

Monosodium Phosphate Sodium Biphosphate Monosodium Dihydrogen Phosphate... 

Mixed Carbohydrase and Protease, 20 Modified Cellulose, 11 Monoammonium Phosphate, 4 Monobasic Potassium Phosphate, 40 Monobasic Sodium Phosphate, 54 Monopotassium Phosphate, 40 Monosodium Dihydrogen Phosphate, 54 Monosodium Phosphate, 54... 

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