Calcium bicarbonate
From Wikipedia, the free encyclopedia
| Calcium bicarbonate | |
|---|---|
| Image:Hydrogencarbonat.PNG | |
| General | |
| Systematic name | Calcium bicarbonate |
| Other names | Calcium hydrogencarbonate |
| Chemical formula | Ca(HCO3)2 |
| SMILES | ? |
| Molar mass | 162.11464 g/mol |
| Appearance | ? |
| CAS number | [?-?-?] |
| Properties | |
| Density and phase | ? g/cm3, ? |
| Solubility in water | 16.6 g/100 ml (20°C) |
| Melting point | ?°C (? K) |
| Boiling point | ?°C (? K) |
| Acidity (pKa) | ? |
| Basicity (pKb) | ? |
| Chiral rotation [α]D | ?° |
| Viscosity | ? cP at ?°C |
| Structure | |
| Molecular shape | ? |
| Coordination geometry |
? |
| Crystal structure | ? |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | ? |
| NFPA 704 | |
| Flash point | ?°C |
| R/S statement | R: ? S: ? |
| RTECS number | ? |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Other anions | ? |
| Other cations | ? |
| Related ? | ? |
| Related compounds | ? |
| Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references |
|
Calcium bicarbonate (Ca(HCO3)2), also called calcium hydrogencarbonate, is a chemical compound which exists only in solution. If a solution evaporates, the following reaction occurs: Ca(HCO3)2(aq) → CO2(g) + H2O(l) + CaCO3(s).
Calcium bicarbonate is formed when water containing carbon dioxide in solution (also known as carbonic acid) reacts with calcium carbonate.
This reaction is very important to the formation of stalactites, stalagmites, columns, and other speleothems within caves and, for that matter, in the formation of the caves themselves. Water containing atmospheric carbon dioxide passes through limestone, or other calcium carbonate containing minerals, converting part of the calcium carbonate to the bicarbonate, which is very water-soluble. Later, in drier conditions, or upon a rise in temperature, the excess carbon dioxide is released from the solution of the bicarbonate, causing the much less soluble calcium carbonate to be deposited.
The reaction is very temperature-sensitive, with a rise in temperature easily driving carbon dioxide out of the calcium bicarbonate solution.
