Triphosphoric acid

Triphosphoric acid
Names
	IUPAC name Diphosphono hydrogenphosphate
	Systematic IUPAC name Triphosphoric acid; Tripolyphosphoric acid
	Other names Diphosphonophosphoric acid; Phosphono trihydrogenpyrophosphate; Phosphonopyrophosphoric acid
Identifiers
CAS Number	10380-08-2 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:39949 ;
ChemSpider	958 ;
ECHA InfoCard	100.030.752
EC Number	233-840-3;
KEGG	C00404 ;
PubChem CID	983;
UNII	NU43IAG5BC ;
CompTox Dashboard (EPA)	DTXSID7047483 ;
	InChI InChI=1S/H5O10P3/c1-11(2,3)9-13(7,8)10-12(4,5)6/h(H,7,8)(H2,1,2,3)(H2,4,5,6) Key: UNXRWKVEANCORM-UHFFFAOYSA-N ;
	SMILES OP(=O)(O)OP(=O)(O)OP(=O)(O)O;
Properties
Chemical formula	H5P3O10
Molar mass	257.95 g/mol
Acidity (pKa)	See body
Conjugate base	Triphosphate
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Corrosive (C)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Triphosphoric acid (also tripolyphosphoric acid), with formula H₅P₃O₁₀, is a condensed form of phosphoric acid. In the family of phosphoric acids, it is the next polyphosphoric acid after pyrophosphoric acid, H₄P₂O₇, also called diphosphoric acid.

Compounds such as ATP (adenosine triphosphate) are esters of triphosphoric acid.

Triphosphoric acid has not been obtained in crystalline form. The equilibrium mixture with an overall composition corresponding to H₅P₃O₁₀ contains about 20% of triphosphoric acid. A solution of the pure species can be obtained by ion exchange of the sodium salt, sodium triphosphate, at 0 °C.^[1]

Triphosporic acid is a pentaprotic acid, meaning that it can release five protons in basic enough conditions. Sources differ on the corresponding pK_a values:

1.0; 2.2; 2.3; 5.7; 8.5^[1]
1.0; 2.2; 2.3; 3.7; 8.5^[2]
small; small; 2.30; 6.50; 9.24^{[citation needed]}

References

^ ^a ^b Corbridge, D. (1995). "Chapter 3: Phosphates". Studies in inorganic Chemistry vol. 20. Elsevier Science B.V. pp. 169–305. ISBN 0-444-89307-5.
^ Holleman, Arnold Frederik; Wiberg, Egon (2001), Wiberg, Nils (ed.), Inorganic Chemistry, translated by Eagleson, Mary; Brewer, William, San Diego/Berlin: Academic Press/De Gruyter, p. 729, ISBN 0-12-352651-5