Potassium bicarbonate (also known as potassium hydrogen carbonate or potassium acid carbonate) is the inorganic compound with the chemical formula KHCO3. It is a white solid.
potassium hydrogen carbonate
potassium acid carbonate
3D model (JSmol)
|E number||E501(ii) (acidity regulators, ...)|
CompTox Dashboard (EPA)
|Molar mass||100.115 g/mol|
|Melting point||292 °C (558 °F; 565 K) (decomposes)|
|22.4 g/100 mL (20 °C)|
|Solubility||practically insoluble in alcohol|
Std enthalpy of
|Safety data sheet||MSDS|
|R-phrases (outdated)||R36 R37 R38|
|NFPA 704 (fire diamond)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|> 2000 mg/kg (rat, oral)|
Potassium hydrogen phosphate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Production and reactivity
- K2CO3 + CO2 + H2O → 2 KHCO3
Decomposition of the bicarbonate occurs between 100 and 120 °C (212 and 248 °F):
- 2 KHCO3 → K2CO3 + CO2 + H2O
This reaction is employed to prepare high purity potassium carbonate.
Potassium bicarbonate is often found added to club soda to improve taste, and to soften the effect of effervescence.
Potassium bicarbonate is used as a fire suppression agent ("BC dry chemical") in some dry chemical fire extinguishers, as the principal component of the Purple-K dry chemical, and in some applications of condensed aerosol fire suppression. It is the only dry chemical fire suppression agent recognized by the U.S. National Fire Protection Association for firefighting at airport crash rescue sites. It is about twice as effective in fire suppression as sodium bicarbonate.
The word saleratus, from Latin sal æratus meaning "aerated salt", was widely used in the nineteenth century for both potassium bicarbonate and sodium bicarbonate. The term has now fallen out of common usage.
- H. Schultz, G. Bauer, E. Schachl, F. Hagedorn, P. Schmittinger (2005). "Potassium Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_039.CS1 maint: uses authors parameter (link)
- Goldberg, Robert N.; Kishore, Nand; Lennen, Rebecca M. (2003). "Thermodynamic quantities for the ionization reactions of buffers in water". In David R. Lide (ed.). CRC handbook of chemistry and physics (84th ed.). Boca Raton, FL: CRC Press. pp. 7–13. ISBN 978-0-8493-0595-5. Retrieved 6 March 2011.
- "Why Your Bottled Water Contains Four Different Ingredients". Time Magazine.
- "Purple-K-Powder". US Naval Research Laboratory. Retrieved 8 February 2012.
- "Potassium Bicarbonate Handbook" (PDF). Armand Products Company.
- "Use of Baking Soda as a Fungicide".
- "Powdery Mildew - Sustainable Gardening Australia". Archived from the original on 2016-03-03.
- "Organic Fruit Production in Michigan".
- "Efficacy of Armicarb (potassium bicarbonate) against scab and sooty blotch on apples" (PDF).