Sodium aluminium phosphate

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Sodium aluminium phosphate
Identifiers
AbbreviationsSALP, SAlP
CAS number10305-76-7 YesY
PubChem3032541
EC number232-090-4
Properties
Molecular formulaNaH14Al3(PO4)8·4H2O
Molar mass144.943 g/mol
Appearancewhite powder
Odorodorless
Solubility in waterinsoluble
Solubilitysoluble in HCl
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references
 
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Sodium aluminium phosphate
Identifiers
AbbreviationsSALP, SAlP
CAS number10305-76-7 YesY
PubChem3032541
EC number232-090-4
Properties
Molecular formulaNaH14Al3(PO4)8·4H2O
Molar mass144.943 g/mol
Appearancewhite powder
Odorodorless
Solubility in waterinsoluble
Solubilitysoluble in HCl
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Sodium aluminium phosphate (SAlP) describes the inorganic compounds with consisting of sodium salts of aluminium phosphates. The most common SAlP has the formula NaH14Al3(PO4)8·4H2O and Na3H15Al2(PO4)8.[1] These materials are prepared by combining alumina, phosphoric acid, and sodium hydroxide.[2]

In addition to the usual hydrate, an anhydrous SAlP is also known, Na3H15Al2(PO4)8 (CAS#10279-59-1), referred to as 8:2:3, reflecting the ratio of phosphate to aluminium to sodium. Additionally an SAlP of ill-defined stoichiometry is used (NaxAly(PO4)z (CAS# 7785-88-8).[3]

The acidic sodium aluminium phosphates are used as acids for baking powders for the chemical leavening of baked goods. Upon heating, SAlP combines with the baking soda to give carbon dioxide. Most of its action occurs at baking temperatures, rather than when the dough or batter is mixed at room temperature. SAlPs are advantageous because they impart a neutral flavor.

As a food additive it has the E number E541..[4][5] Basic sodium aluminium phosphates are also known, e.g., Na15Al3(PO4)8. These species are useful in cheese making.[2]

References[edit]

  1. ^ Klaus Schrödter, Gerhard Bettermann, Thomas Staffel, Friedrich Wahl, Thomas Klein, Thomas Hofmann "Phosphoric Acid and Phosphates" in Ullmann’s Encyclopedia of Industrial Chemistry 2008, Wiley-VCH, Weinheim. doi:10.1002/14356007.a19_465.pub3
  2. ^ a b "Phosphoric Acids and Phosphates" David R. Gard, 2005, Wiley-VCH. doi:10.1002/0471238961.1608151907011804.a01.pub2
  3. ^ Lucina E. Lampila "Applications and functions of food-grade phosphates" Ann. N.Y. Acad. Sci. 2013, vol. 1301, pp. 37–44. Template:DOI!10.1111/nyas.12230
  4. ^ Brooks, David W. "Leavening Agents". Teaching and Research Web Site. University of Nebraska - Lincoln. Retrieved 2011-03-06. 
  5. ^ "E541 : Sodium aluminum phosphate". Food-Info. Wageningen University. Retrieved 2011-03-06.