Dipotassium phosphate

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Dipotassium phosphate
Di-potassium monohydrogen phosphate.svg
Hydrogenfosforečnan draselný.JPG
IUPAC names
Potassium hydrogenphosphate
Potassium hydrogen(tetraoxidophosphate)(2−)
Systematic IUPAC name
Potassium hydroxidotrioxidophosphate(2−)
Other names
Potassium monohydrogen phosphate
Phosphoric acid dipotassium salt
Potassium phosphate dibasic
3D model (JSmol)
ECHA InfoCard 100.028.940
EC Number 231-834-5
E number E340(ii) (antioxidants, ...)
Molar mass 174.2 g/mol
Appearance white powder
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
NFPA 704
Flammability code 0: Will not burn. E.g. waterHealth code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond
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).
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Infobox references

Dipotassium phosphate (K2HPO4) (also 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.

A dipotassium phosphate solution is formed by the stoichiometric reaction of phosphoric acid with two equivalents of potassium hydroxide:

H3PO4 + 2 KOH → K2HPO4 + 2 H2O


As a food additive, dipotassium phosphate is used in imitation dairy creamers, dry powder beverages, mineral supplements, and starter cultures.[1] It is used in non-dairy creamers to prevent coagulation.[2]

Dipotassium phosphate is also used to make buffer solutions and it is used in the production of trypticase soy agar which is used to make agar plates for culturing bacteria.[citation needed]

A 3% gel of dipotassium phosphate is used as the active ingredient in Crest Sensi-Strips, a common tooth sensitivity product.

Used in the fire suppression industry to flush agent distribution lines in restaurant fire protection systems.


As a food additive, dipotassium phosphate is categorized in the United States by the Food and Drug Administration as generally recognized as safe (GRAS).[3]


  1. ^ John H. Thorngate iii, Seppo Salminen , Larry A . Branen , and Michael P . Davidson, eds. (2001). "Food Phosphates". Food Additives. CRC Press. doi:10.1201/9780824741709.ch25. ISBN 978-0-8247-9343-2.CS1 maint: uses editors parameter (link)
  2. ^ "dipotassium phosphate". Retrieved 2009-01-06. (uses: Food Industry)
  3. ^ "Database of Select Committee on GRAS Substances (SCOGS) Reviews". Retrieved 2008-03-22. (listed as "potassium phosphate, dibasic")

The compound is for food uses although it may be bad for consumers to eat vast amounts of it.