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| Names | |
|---|---|
| IUPAC name potassium hydrogen carbonate | |
| Other names potassium acid carbonate | |
| Identifiers | |
3D model (JSmol) | |
| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.005.509  |
| EC Number |
|
| E number | E501(ii) (acidity regulators, ...) |
PubChem CID | |
| UNII | |
CompTox Dashboard (EPA) | |
| |
SMILES
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| Properties | |
Chemical formula | KHCO3 |
| Molar mass | 100.115 g/mol |
| Appearance | white crystals |
| Odor | odorless |
| Density | 2.17 g/cm3 |
| Melting point | 292 °C (558 °F; 565 K) (decomposes) |
| 22.4 g/100 mL (20 °C)[1] | |
| Solubility | practically insoluble in alcohol |
| Acidity (pKa) | 10.329[2] 6.351 (carbonic acid)[2] |
| Thermochemistry | |
Std enthalpy of formation (ΔfH⦵298) | -963.2 kJ/mol |
| Pharmacology | |
| A12BA04 (WHO) | |
| Hazards | |
| Safety data sheet | MSDS |
| R-phrases (outdated) | R36 R37 R38 |
| NFPA 704 (fire diamond) | |
| Flash point | Non-Flammable |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | > 2000 mg/kg (rat, oral) |
| Related compounds | |
Other anions | Potassium carbonate |
Other cations | Sodium bicarbonate Ammonium bicarbonate |
Related compounds | Potassium bisulfate Potassium hydrogen phosphate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
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.[1]
)
Production and reactivity
It is manufactured by treating an aqueous solution of potassium carbonate with carbon dioxide:[1]
- 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.
Uses
Food and drink
This compound is a source of carbon dioxide for leavening in baking. It can substitute for baking soda (sodium bicarbonate) for those with a low-sodium diet,[3] and it is an ingredient in low-sodium baking powders.[4][5]
As an inexpensive, nontoxic base, it is widely used in diverse application to regulate pH or as a reagent. Examples include as buffering agent in medications, an additive in winemaking.
Potassium bicarbonate is often found added to club soda to improve taste,[6] and to soften the effect of effervescence.
Fire extinguishers
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.[7]
Agriculture
Potassium bicarbonate has widespread use in crops, especially for neutralizing acidic soil.[8]
Potassium bicarbonate is an effective fungicide against powdery mildew and apple scab, allowed for use in organic farming.[9][10][11][12]
History
The word saleratus, from Latin sal æratus meaning "aerated salt", first used in the nineteenth century, refers to both potassium bicarbonate and sodium bicarbonate.[13]
References
- ^ a b c 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. ISBN 3527306730.
- ^ a b 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.
- ^ "Potassium Bicarbonate". encyclopedia.com. Cengage. Retrieved May 29, 2020.
- ^ "Home cooking with less salt". harvard.edu. Harvard University. Retrieved May 29, 2020.
- ^ Wilkens, Katy G. "You Have the (Baking) Power with Low-Sodium Baking Powders". agingkingcounty.org. Aging & Disability Services for Seattle & King County. Retrieved May 29, 2020.
- ^ "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". Archived from the original on 2010-05-07. Retrieved 2010-02-14.
- ^ "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).
- ^ "saleratus". merriam-webster.com. Merriam-Webster. Retrieved May 29, 2020.