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.
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Names | |
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IUPAC name
Potassium hydrogen phosphate
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Other names
Potassium monohydrogen phosphate
Phosphoric acid dipotassium salt Potassium phosphate dibasic | |
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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) | <imagemap>
File:NFPA 704.svg|80px|alt=NFPA 704 four-colored diamond poly 150 150 300 300 150 450 0 300 Health 1: Exposure would cause irritation but only minor residual injury. E.g. turpentine poly 300 0 450 150 300 300 150 150 Flammability 0: Will not burn. E.g. water poly 450 150 600 300 450 450 300 300 Instability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogen poly 300 300 450 450 300 600 150 450 Special hazards (white): no code desc none </imagemap> |
Flash point | Non-flammable |
Related compounds | |
Other cations
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Disodium phosphate Diammonium phosphate |
Related compounds
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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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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
- ^ 1.0 1.1 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.
- ^ 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. ISBN 978-0-8247-9343-2.
- ^ "What is dipotassium phosphate?". 30 April 2018. Retrieved 2020-09-09.
- ^ "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")
- ^ "Brands Of Bottled Water With Electrolytes (Confirmed By Lab Tests) - Water Purification Guide".