Dipotassium phosphate

Dipotassium phosphate
Names
IUPAC name
Potassium hydrogen phosphate
Other names
Potassium monohydrogen phosphate
Phosphoric acid dipotassium salt
Potassium phosphate dibasic
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.028.940 Edit this at Wikidata
EC Number
  • 231-834-5
E number E340(ii) (antioxidants, ...)
UNII
  • InChI=1S/2K.H3O4P/c;;1-5(2,3)4/h;;(H3,1,2,3,4)/q2*+1;/p-2 checkY
    Key: ZPWVASYFFYYZEW-UHFFFAOYSA-L checkY
  • InChI=1/2K.H3O4P/c;;1-5(2,3)4/h;;(H3,1,2,3,4)/q2*+1;/p-2
    Key: ZPWVASYFFYYZEW-NUQVWONBAH
  • [K+].[K+].[O-]P([O-])(=O)O
Properties
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
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)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
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).
X markN verify (what is checkYX markN ?)

Dipotassium phosphate (also dipotassium hydrogen orthophosphate or 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. It is a white or colorless solid that is soluble in water.

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

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. It functions as an emulsifier, stabilizer and texturizer; it is also a buffering agent, and chelating agent especially for the calcium in milk products.

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

References

  1. 1 2 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 978-3-527-30673-2.
  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 12 July 2025). ISBN 978-0-8247-9343-2.{{cite book}}: CS1 maint: DOI inactive as of July 2025 (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". 3 July 2021.