| Potassium bicarbonate | |
|---|---|
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potassium hydrogen carbonate |
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Other names
potassium acid carbonate |
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| Identifiers | |
| CAS number | 298-14-6 |
| PubChem | 516893 |
| EC number | 206-059-0 |
| Properties | |
| Molecular formula | KHCO3 |
| Molar mass | 100.115 g/mol |
| Appearance | white crystals |
| Odor | odorless |
| Density | 2.17 g/cm3 |
| Melting point |
Decomposes |
| Solubility in water | 33.7 g/100 mL (20 °C) 60 g/100 mL (60 °C) |
| Solubility | practically insoluble in alcohol |
| Acidity (pKa) | 10.329[1]
6.351 (carbonic acid)[1] |
| Hazards | |
| MSDS | MSDS |
| EU Index | Not listed |
| R-phrases | R36 R37 R38 |
| NFPA 704 |
0
1
0
|
| Flash point | Non-Flammable |
| Related compounds | |
| Other anions | Potassium carbonate |
| Other cations | Sodium bicarbonate Ammonium bicarbonate |
| Related compounds | Potassium bisulfate Potassium hydrogen phosphate |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Potassium bicarbonate (also known as potassium hydrogen carbonate or potassium acid carbonate), is a colorless, odorless, slightly basic, salty substance. According to the US Food and Drug Administration (FDA), potassium bicarbonate is "generally recognized as safe".[2]
Potassium bicarbonate is soluble in water, and is often found added to bottled water to affect taste; however, it is not soluble in alcohol. Decomposition of the substance occurs between 100 °C and 120 °C into K2CO3 (potassium carbonate), H2O (water), and CO2 (carbon dioxide). In concentrations greater than 0.5%, KHCO3 can have toxic effects on plants (potassium bicarbonate has widespread use in crops, especially for neutralizing acidic soil, and is also under consideration as an organic fungicide[3]), although there is no evidence of human carcinogenicity, no adverse effects of overexposure, and an undetermined LD50.
Physically, potassium bicarbonate occurs as a crystal or a soft white granular powder. It is manufactured by reacting potassium carbonate with carbon dioxide and water:
Potassium bicarbonate is very rarely found in its natural form, the mineral called kalicinite.
Contents |
The compound is used as a source of carbon dioxide for leavening in baking, extinguishing fire in dry chemical fire extinguishers, acting as a reagent, and a strong buffering agent in medications.
It is used as an additive in winemaking and as a base in foods and to regulate pH. It is a common ingredient in club soda, where it is used 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 National Fire Protection Association for firefighting at airport crash rescue sites. It is about twice as effective in fire suppression as sodium bicarbonate. [1]
Potassium bicarbonate is an effective fungicide against powdery mildew, allowed for use in organic farming.[4] [5]
The word saleratus, from Latin sal æratus meaning "aerated salt", was widely used in the 19th century for both potassium bicarbonate and sodium bicarbonate. The term has now fallen out of common usage.
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