Sodium Triphosphate, 385,

Traditionally, phosphates have been represented as stoichiometric combinations of oxides. It is common practice to speak of the phosphates in terms of oxide ratios for example, phosphoric acid [7664-38-2] H PO, as 1.5 H2O 0.5P2O disodium phosphate [7558-79-4] Na2HP04, as Na20 O.5H2O 0.5P20 and sodium triphosphate [7601-54-9], Na P O, as 2.5 Na20 1.5P20. ... 

BuHders, eg, sodium triphosphate and nonphosphate buHders such as zeoHte and citrate, remove free calcium from the washing solution. 

Detergency was ascertained as the quotient of the whiteness obtained and the whiteness which is theoretically possible, expressed as a percentage. Samples of artificial soiled fabrics are washed under given conditions. Aqueous solutions of alkanephosphonic acid bisdiisopropanolamides show a notable detergency without addition of a builder, e.g., sodium triphosphate [190] see Table 12. 

The sodium salts of these acids, sodium pyrophosphate (Na4 P2 O7) and sodium triphosphate (Nas P3 Oio), have been used widely in detergents. The polyphosphate anions are good additives for cleansing agents because... 

The category of builders consists predominantly of several types of materials -specific precipitating alkaline materials such as sodium carbonate and sodium silicate complexing agents like sodium triphosphate or nitrilotriacetic acid (NTA) and ion exchangers, such as water-soluble polycarboxylic acids and zeolites (e.g., zeolite A). 

Biofilms Sodium ethylenediaminetetraaceticacid (Na-EDTA), sodium triphosphate, trisodium phosphate... 

STP, sodium triphosphate SPP, sodium pyrophosphate SP, sodium phytate. 

A second group embraces the pyrophosphates and the analogous sodium triphosphate, Na6P3Oio, discovered by Schwarz (268) and confirmed by Stange (273). These were formulated as salts of chain-like anions, as were derivatives with other cations. 

Fig. 5. The oxygen coordination of the Na+ ions in the form I of sodium triphosphate, Na5PjOio.

Both forms of anhydrous sodium triphosphate are unstable with respect to combination with water, and cannot therefore be prepared from aqueous solution. Likewise they cannot be obtained by dehydration of the hexahydrate (19, 141, 142, 326) as long as the dehydration temperature is less than 150°C. When the hexahydrate is heated in an open atmosphere to about 120° it first loses only about five molecules of water (238, 317). The residual molecule of water simultaneously causes hydrolysis and splits the triphosphate anion to crystalline diphosphate and amorphous monophosphate, perhaps according to the equation ... 

The method using pH determinations, for example, depends on the fact that the pH of a solution of sodium triphosphate is decreased by the addition of salts containing the cation under investigation—c.g., NaCl or CaCl2 95, 248, 345). The quantity of H+ ions set free in this way is determined potentiometrically and the formation constant of the complex is determined on the basis of the equilibria involved, such as ... 

One of the special methods mentioned above may be used in determining the two forms of sodium triphosphate, one of which (Na6P3Oio(I)) is unde-... 

Phosphates, molybdates, and (at high pH) silicates act as anodic inhibitors much as do alkalis, except that the iron oxides/hydroxides formed on anodic sites then contain some PO43-, M0O42-, or Si044- ( basic iron phosphates, etc.). These inhibitors require the presence of 02 to produce basic iron(III) phosphate, molybdate, or silicate films, whereas oxidizing anions such as chromates and nitrites oxidize Fe2+ (aq) rapidly to insoluble iron(III) oxides on anodic sites. Dianodic inhibitors combine complementary inhibition mechanisms for example, sodium triphosphate may be used with sodium chromate, or sodium molybdate with NaN02. 

Condensed polyphosphates such as sodium triphosphate are of great industrial importance since they arc used in large tonnages as "builders" in the manufacture of detergents. As such they function to adjust the pH and to complex water-hardening ions such as Ca2+ and Mg2+.17 Industrially, sodium triphosphate is rot made from the reaction of Eq. 16.12 but from dehydration of sodium hydrogen phosphate and sodium dihydrogen phosphate mixtures ... 

A widely applicable masking agent is sodium triphosphate, Na5P3Oi0-6H2O, which readily complexes with a very wide variety of cations in all groups of the Periodic Table, preventing their precipitation by alkali hydroxide, ammonia, phosphate, carbonate or borate. It is used commercially as Calgon to mask calcium which cannot then form precipitates with citrate, fluoride or oxalate ions and in many other instances (see Table 3). 

Sodium triphosphate, Na5P3Oio, in synthetic detergents can contribute to the eutrophication of rivers and lakes. 

Sodium trihydroxothioferrate(II), Na3FeS(OH)s, formation of, in preparation of potassium dithioferrate(III), 6 170 Sodium trimetaphosphimates, 6 80 Na3(P02NH)3, 1-hydrate, 6 99 4-hydrate, purification and acid hydrolysis of, for preparation of pentasodium diimidotri-phosphate, 6 105 Na3(P02NH)3-NaOH-7H20, 6 80 Sodium triphosphate (tripolyphosphate), 3 101 6-hydrate, 3 103... 

Sodium triphosphate (sodium tripolyhosphate) is manufactured by mixing phosphoric acid and sodium carbonate (soda ash) in the calculated amounts to give a 1 2 ratio of monosodium and disodium phosphates and then heating to effect dehydration at 300 to 500°C. 

Sodium triphosphate is used almost solely in one type of product detergents. Some detergents contain up to 50% by weight sodium triphosphate. It has the unique property of complexing or sequestering dipositive ions such as calcium (Ca2+) and magnesium (Mg2+) that are present in water. Tide is an example of a phosphate detergent that has been used for at least 5 decades. 

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