Triphosphoric acid

Triphosphoric acid
Names
	IUPAC name Diphosphono hydrogen phosphate
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)	small, small, 2.30, 6.50, 9.24
Conjugate base	Triphosphate
Hazards
Main hazards	Corrosive (C)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

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. Various pK_a values are reported, 1.0 ; 2.2 ; 2.3 ; 5.7 ; 8.5,^[1] 1.0 ; 2.2 ; 2.3 ; 3.7 ; 8.5 ^[2]

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

[StudiesinInorganicvol20-1] Corbridge, D. (1995). "Chapter 3: Phosphates". Studies in inorganic Chemistry vol. 20. Elsevier Science B.V. pp. 169–305. ISBN 0-444-89307-5.

[2] 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

[1]

[2]

Names


IUPAC name Diphosphono hydrogen phosphate
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 (pK_a)	small, small, 2.30, 6.50, 9.24
Conjugate base	Triphosphate
Hazards
Main hazards	Corrosive (C)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).