Calcium bicarbonate

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Calcium bicarbonate
Names
IUPAC name
Calcium hydrogen carbonate
Other names
Cleansing lime
Properties
Ca(HCO3)2
Molar mass 162.11464 g/mol
Appearance Unstable solution
Odor Odorless
Melting point Decomposes
Boiling point Decomposes
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
Hazards
Safety data sheet None
Flash point Non-flammable
Related compounds
Related compounds
Calcium carbonate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

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.

Properties

Chemical

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

Physical

Calcium bicarbonate can only exist in an aq. solution, thus all of its properties are those of its solution.

Availability

Calcium bicarbonate solutions are not sold by chemical suppliers due to their instability and thus have to be made in situ.

Preparation

Calcium bicarbonate can be made by bubbling an excess of carbon dioxide through an aq. suspension of calcium carbonate until all the carbonate dissolves.

CaCO3(s) + CO2 → Ca(HCO3)2(aq)

Projects

  • Neutralize acids
  • Purify calcium carbonate
  • Dissolve limestone

Handling

Safety

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.

Storage

Calcium bicarbonate cannot be stored for long periods of time.

Disposal

No special disposal is required. Discard it as you with.

References

Relevant Sciencemadness threads