| IUPAC name
Calcium hydrogen carbonate
| Other names
|Molar mass||162.11464 g/mol|
| 16.1 g/100 ml (0 °C)|
16.6 g/100 ml (20 °C)
18.4 g/100 ml (100 °C)
|Solubility||Reacts with acids|
|Safety data sheet||None|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Calcium bicarbonate, also called calcium hydrogen carbonate, is an unstable inorganic chemical compound with the chemical formula Ca(HCO3)2.
The compound cannot be isolated in solid form as it decomposes to calcium carbonate and carbon dioxide upon removal of water via either boiling or vacuum drying. It exists only in aqueous solution containing the calcium (Ca2+), bicarbonate (HCO−
3), and carbonate (CO2−
3) ions, together with dissolved carbon dioxide (CO2). The relative concentrations of these carbon-containing species depend on the pH: bicarbonate predominates within the range 6.36–10.25 in fresh water.
Solutions of calcium carbonate react with acids forming calcium salts of said acids and releasing carbon dioxide.
- Ca(HCO3)2 + 2 HX → CaX2 + 2 H2O + 2 CO2
Calcium bicarbonate can only exist in an aq. solution, thus all of its properties are those of its solution.
Calcium bicarbonate solutions are not sold by chemical suppliers due to their instability and thus have to be made in situ.
- CaCO3(s) + CO2 → Ca(HCO3)2(aq)
- Neutralize acids
- Purify calcium carbonate
- Dissolve limestone
Calcium bicarbonate solution has low toxicity and it's generally considered safe to handle. Avoid handling it in closed bottles to prevent a pressure build-up inside the container.
Calcium bicarbonate cannot be stored for long periods of time.
No special disposal is required. Discard it as you with.