Dipotassium phosphate

Dipotassium phosphate
IUPAC name Potassium hydrogen phosphate
Other names Potassium monohydrogen phosphate Phosphoric acid dipotassium salt Potassium phosphate dibasic
Identifiers
CAS number	7758-11-4 Y
PubChem	24450
ChemSpider	22858 Y
UNII	CI71S98N1Z Y
Jmol-3D images	Image 1
SMILES [K+].[K+].[O-]P([O-])(=O)O
InChI InChI=1S/2K.H3O4P/c;;1-5(2,3)4/h;;(H3,1,2,3,4)/q2*+1;/p-2 Y Key: ZPWVASYFFYYZEW-UHFFFAOYSA-L Y InChI=1/2K.H3O4P/c;;1-5(2,3)4/h;;(H3,1,2,3,4)/q2*+1;/p-2 Key: ZPWVASYFFYYZEW-NUQVWONBAH
Properties
Molecular formula	K2HPO4
Molar mass	174.2 g/mol
Appearance	white powder deliquescent
Odor	odorless
Density	2.44 g/cm3
Melting point	>465 °C decomp.
Solubility in water	149.25 g/100 mL (20 °C)
Solubility	slightly soluble in alcohol
Acidity (pKa)	12.4
Basicity (pKb)	6.8
Hazards
EU Index	Not listed
NFPA 704	0 2 0
Flash point	Non-flammable
Related compounds
Other cations	Disodium phosphate Diammonium phosphate
Related compounds	Monopotassium phosphate Tripotassium phosphate
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Dipotassium phosphate (K₂HPO₄) - also phosphoric acid, dipotassium salt; dipotassium hydrogen orthophosphate; potassium phosphate, dibasic - is a highly water-soluble salt which is often used as a fertilizer, food additive and buffering agent. It is a common source of phosphorus and potassium.

The pH of a dipotassium phosphate solution is almost neutral. It is formed by the stoichiometric neutralization of phosphoric acid with potassium hydroxide:

H₃PO₄ + 2 KOH → K₂HPO₄ + 2 H₂O

It reacts with phosphoric acid to generate monopotassium phosphate:

K₂HPO₄ + H₃PO₄ → 2 KH₂PO₄

Safety

As a food additive, Dipotassium phosphate is on the FDA's Generally recognized as safe, or GRAS, list of substances^[1]. It is used in non-dairy creamers to prevent coagulation.^[2]

References

1. ^ "Database of Select Committee on GRAS Substances (SCOGS) Reviews". http://www.cfsan.fda.gov/~dms/opascogd.html. Retrieved 2008-03-22.  (listed as potassium phosphate, dibasic)
2. ^ "dipotassium phosphate". http://everything2.com/e2node/dipotassium%2520phosphate. Retrieved 2009-01-06.  (uses: Food Industry)