Triphosphoric acid (also tripolyphosphoric acid), with formula H
5P
3O
10, is a
condensed form of
phosphoric acid
Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, w ...
. In the family of
phosphoric acids Phosphoric may refer to:
*Phosphoric acid
*Phosphoric anhydride, see phosphorus pentoxide
See also
*Phosphorus
Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white ph ...
, it is the next polyphosphoric acid after
pyrophosphoric acid
Pyrophosphoric acid, also known as diphosphoric acid, is the inorganic compound with the formula H4P2O7 or, more descriptively, HO)2P(O)sub>2O. Colorless and odorless, it is soluble in water, diethyl ether, and ethyl alcohol. The anhydrous acid c ...
, H
4P
2O
7, also called diphosphoric acid.
Compounds such as ATP (
adenosine triphosphate
Adenosine triphosphate (ATP) is an organic compound that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms o ...
) are
ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides a ...
s of triphosphoric acid.
Triphosphoric acid has not been obtained in crystalline form. The equilibrium mixture with an overall composition corresponding to H
5P
3O
10 contains about 20% of triphosphoric acid. A solution of the pure species can be obtained by ion exchange of the sodium salt,
sodium triphosphate
Sodium triphosphate (STP), also sodium tripolyphosphate (STPP), or tripolyphosphate (TPP), , at 0 °C.
Triphosporic acid is a
pentaprotic acid, meaning that it can release five protons in basic enough conditions. Sources differ on the corresponding p''K''
a values:
* 1.0; 2.2; 2.3; 5.7; 8.5
* 1.0; 2.2; 2.3; 3.7; 8.5
* small; small; 2.30; 6.50; 9.24
References
Phosphorus oxoacids
Phosphorus(V) compounds
{{Inorganic-compound-stub