Sodium orthophosphates

Fig. 6. Phase diagram of the Na20—H2O—P20 (sodium orthophosphate) system at 25°C.

The solubihty of a number of sodium orthophosphates is depicted in Figure 7. Some of the sodium phosphates dissolve or precipitate incongmendy, affording a different Na20/P20 ratio in the solution phase from that of the soHd phase. Sodium phosphates that precipitate are also a function of the temperature. As the temperature increases, the sodium phosphates that may precipitate from solution tend to be anhydrous or lower hydrates than those equiUbrium sodium phosphate phases at lower temperature. Whereas most of the phases in Figure 7 represent congmentiy soluble sodium phosphates, soHd phases appear or disappear upon changes in temperature. 

Fig. 7. Solubihty of sodium orthophosphates as a function of temperature (17,18). MSP, DSP, and TSP are mono-, di-, and trisodium phosphates,...

Lithium orthophosphates are unimportant and differ from the other alkali metal phosphates in being insoluble. At least 10 crystalline hydrated or anhydrous sodium orthophosphates are known and these can be grouped into three series ... 

Figure 10.1 Types of phosphate structures, (a) Where x = 12 to 14, the structure represents sodium polyphosphate, a phosphate typically used in HW heating and industrial steam boiler formulations. The structure is ill defined and described as glassy rather than crystalline. Where x = 2, it represents sodium tripolyphosphate, (b) This is the structure where effectively, x = 0, and represents trisodium phosphate (sodium orthophosphate), which is commonly supplied in either crystalline or anhydrous powder form and used as an alkalinity booster, boiler boil-out cleaner, and metal surfaces passivator.

Benzotriazole l,3-dimethyl-2-thiourea, thiourea, sodium-hexa-metaphosphate Tribasic sodium orthophosphate with polyurethane foam° [200]... 

Various polyphosphates are effective sequestering agents under appropriate conditions. The best known of these is sodium hexametaphosphate (10.14), the cyclic hexamer of sodium orthophosphate. Further examples are the cyclic trimer sodium trimetaphosphate (10.15), as well as the dimeric pyrophosphate (10.16), the trimeric tripolyphosphate (10.17) and other linear polyphosphates (10.18). All of these polyanions function by withdrawing the troublesome metal cation into an innocuous and water-soluble complex anion by a process of ion exchange as shown in Scheme 10.7 for sodium hexametaphosphate. Hence these compounds are sometimes referred to as ion-exchange agents. 

Sodium nitroprusside, 74 536 Sodium nonoxynol-25 sulfate cosmetic surfactant, 7 834t Sodium oleoyl isethionate cosmetic surfactant, 7 834t Sodium orthophosphates, 73 8321 Sodium orthosilicates commercial, 22 465, 466t, 469t manufacture of, 22 464, 465 Sodium oxide(s), 2 273, 22 765 in cement, 5 468 contamination by, 22 776 Sodium ozonide, 79 417 Sodium palmitate, as soap, 22 726 Sodium pentaborate... 

Now 4 mol. are required to effect complete hydrolysis to sodium orthophosphate according to equation (c), but only 2 mol. are required either for the removal of fluorine alone and conversion into sodium di-isopropyl phosphate (d) or for conversion into disodium fluorophosphonate (e). To decide between these reactions, half of the above hydrolysis product was rendered acid to bromophenol Hue... 

Nirenberg, Z.. Solenchyk, B.,andYaron, 1. Solnbility in the system sodium orthophosphate, acetone, and water, / Chem.Eng. Data, 22(l) 47-48, 1977. 

See how silver nitrate reacts with a solution of sodium orthophosphate. Note the colour of the precipitate. Write the equation of the reaction. Does the substance dissolve in a 1 A nitric acid solution ... 

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. 

Pour 2 ml of the prepared colloidal iron hydroxide solution into each of several test tubes and add 2 ml of one of the following solutions of the same normality (0.1 N) to each of them sodium chloride, barium chloride, aluminium chloride, sodium sulphate, aluminium sulphate, or monosubstituted sodium orthophosphate. What do you observe How does the coagulating effect of an electrolyte depend on the sign and magnitude of the charge of its ions ... 

Ceramic glazes -strontium carbonate m [STRONTIUM AND STRONTIUM COMPOUNDS] (Vol 22) -use of sodium orthophosphates [PHOSPHORIC ACID AND PHOSPHATES] (Vol 18)... 

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