Potassium bicarbonate, slightly wet, on a watch glass.
| IUPAC name
Potassium hydrogen carbonate
| Other names
Potassium acid carbonate
|Molar mass||100.115 g/mol|
|Appearance||White hygroscopic salt|
|Melting point||292 °C (558 °F; 565 K) (decomposes)|
| 33.7 g/100 mL (20 °C)|
60 g/100 mL (60 °C)
|Solubility|| Reacts with acids|
Insoluble in alcohols, benzene, chloroform, toluene
|Vapor pressure||~0 mmHg|
Std enthalpy of
|Safety data sheet||AcrosOrganics|
|Lethal dose or concentration (LD, LC):|
LD50 (Median dose)
|> 2,000 mg/kg (rat, oral)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Potassium bicarbonate or potassium hydrogen carbonate is a hygroscopic colorless salt of potassium with the formula KHCO3. It is used as a food additive in the European Union, E 501. It can be found in nature as the rare mineral kalicinite.
Potassium bicarbonate decomposes to potassium carbonate if heated above 290 °C, despite some sources claiming the decomposition occurring at 100 or 120 degrees C.
- 2 KHCO3 → K2CO3 + CO2 + H2O
Potassium bicarbonate, like its sodium counterpart will react with acids to form potassium salt of the said acid.
- KHCO3 + HCl → KCl + H2O + CO2
Potassium bicarbonate is a white hygroscopic solid, soluble in water but insoluble in alcohols and other organic solvents.
Potassium bicarbonate is sold by winemaking stores as a pH regulator/buffer. It is more expensive than sodium bicarbonate.
Potassium bicarbonate can be made by bubbling carbon dioxide into a solution containing potassium carbonate.
If you have a mixture of potassium and sodium hydroxide, you can dissolve it in alcohol and then bubble excess carbon dioxide in the solution. As potassium bicarbonate is insoluble in alcohol, it will precipitate, while sodium bicarbonate will stay in solution.
- Make potassium carbonate
- Make potassium salts
- Buffering agent
Potassium bicarbonate is considered safe and doesn't require special handling.
Potassium bicarbonate should be kept in closed bottles. Since it's hygroscopic, it's best to keep it in a desiccator.
No special disposal is required. Discard it as you wish.