Dipotassium phosphate

Dipotassium phosphate (K₂HPO₄) (also dipotassium hydrogen orthophosphate; potassium phosphate dibasic) is the inorganic compound with the formula K₂HPO₄^.(H₂O)_x (x = 0, 3, 6). Together with monopotassium phosphate (KH₂PO₄^.(H₂O)_x), it is often used as a fertilizer, food additive, and buffering agent.^[1] It is a white or colorless solid that is soluble in water.

Dipotassium phosphate

Names
IUPAC name Potassium hydrogen phosphate
Other names Potassium monohydrogen phosphate Phosphoric acid dipotassium salt Potassium phosphate dibasic
Identifiers
CAS Number	7758-11-4 Y 16788-57-1 (trihydrate) Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:131527 N
ChEMBL	ChEMBL1200459 N
ChemSpider	22858 Y
ECHA InfoCard	100.028.940
EC Number	231-834-5
E number	E340(ii) (antioxidants, ...)
PubChem CID	24450
UNII	CI71S98N1Z Y RJK174X3TZ (trihydrate) Y
CompTox Dashboard (EPA)	DTXSID8035506
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
SMILES [K+].[K+].[O-]P([O-])(=O)O
Properties
Chemical formula	K2HPO4
Molar mass	174.2 g/mol
Appearance	white powder deliquescent
Odor	odorless
Density	2.44 g/cm3
Melting point	> 465 °C (869 °F; 738 K) decomposes
Solubility in water	149.25 g/100 mL (20 °C)
Solubility	slightly soluble in alcohol
Acidity (pKa)	12.4
Basicity (pKb)	6.8
Hazards
NFPA 704 (fire diamond)	1 0 0
Flash point	Non-flammable
Related compounds
Other cations	Disodium phosphate Diammonium phosphate
Related compounds	Monopotassium phosphate Tripotassium phosphate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

It is produced commercially by partial neutralization of phosphoric acid with two equivalents of potassium chloride:^[1]

H₃PO₄ + 2 KCl → K₂HPO₄ + 2 HCl

Uses

As a food additive, dipotassium phosphate is used in imitation dairy creamers, dry powder beverages, mineral supplements, and starter cultures.^[2] It functions as an emulsifier, stabilizer and texturizer; it also is a buffering agent, and chelating agent especially for the calcium in milk products..^[3]

As a food additive, dipotassium phosphate is generally recognized as safe by the United States Food and Drug Administration,^[4] and is commonly used (in conjunction with other inorganic salts) to add taste to bottled water.^[5]

References

1. Klaus Schrödter; Gerhard Bettermann; Thomas Staffel; Friedrich Wahl; Thomas Klein; Thomas Hofmann (2012). "Phosphoric Acid and Phosphates". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_465.pub3. ISBN 978-3527306732.
2. John H. Thorngate III; Seppo Salminen; Larry A. Branen; Michael P. Davidson, eds. (2001). "Food Phosphates". Food Additives. Food Science and Technology. Vol. 116. CRC Press. doi:10.1201/9780824741709.ch25 (inactive 2024-11-11). ISBN 978-0-8247-9343-2.{{cite book}}: CS1 maint: DOI inactive as of November 2024 (link)
3. "What is dipotassium phosphate?". 30 April 2018. Retrieved 2020-09-09.
4. "Database of Select Committee on GRAS Substances (SCOGS) Reviews". Archived from the original on 2007-05-21. Retrieved 2008-03-22. (listed as "potassium phosphate, dibasic")
5. "Brands Of Bottled Water With Electrolytes (Confirmed By Lab Tests) - Water Purification Guide".