Calcium bicarbonate and Magnesium bicarbonate: Difference between pages

| Watchedfields = changed

| verifiedrevid = 399701812

| Name = Calcium bicarbonate

| ImageFile = Calcium bicarbonate.png

| ImageName = Calcium bicarbonate

| IUPACName = Calcium hydrogen carbonate

| OtherNames = Calcium bicarbonate

| Section1 = {{Chembox Identifiers

| SMILES = [Ca+2].[O-]C(=O)O.[O-]C(=O)O

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 8351767

| PubChem = 10176262

| InChI = 1/2CH2O3.Ca/c2*2-1(3)4;/h2*(H2,2,3,4);/q;;+2/p-2

| InChIKey = NKWPZUCBCARRDP-NUQVWONBAN

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/2CH2O3.Ca/c2*2-1(3)4;/h2*(H2,2,3,4);/q;;+2/p-2

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = NKWPZUCBCARRDP-UHFFFAOYSA-L

| CASNo =

| RTECS =

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| Section2 = {{Chembox Properties

| Formula = Ca(HCO₃)₂

| MolarMass = 162.11464 g/mol

| Appearance =

| Density =

| Solubility = 16.1 g/100 mL (0 °C) <br> 16.6 g/100 mL (20°C) <br> 18.4 g/100 mL (100 °C)

| MeltingPt =

| BoilingPt =

| pKa =

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| Viscosity =

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| Section3 = {{Chembox Structure

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| Section7 = {{Chembox Hazards

| ExternalMSDS =

| MainHazards = Irritant

| FlashPt = Non-Flammable

| RPhrases = {{R36}}

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| Section8 = {{Chembox Related

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| Related [[?]]

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'''Calcium bicarbonate''' (Ca(HCO₃)₂), also called '''calcium hydrogencarbonate''', does not refer to a known solid compound; it exists only in [[aqueous]] solution containing the [[calcium]] (Ca²⁺), [[bicarbonate]] (HCO₃^–), and [[carbonate]] (CO₃^2–) 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.

All waters in contact with the atmosphere absorb carbon dioxide, and as these waters come into contact with rocks and sediments they acquire metal ions, most commonly calcium and magnesium, so most natural waters that come from streams, lakes, and especially wells, can be regarded as dilute solutions of these bicarbonates. These [[hard water]]s tend to form carbonate scale in pipes and boilers and they react with soaps to form an undesirable scum.

Attempts to prepare compounds such as calcium bicarbonate by evaporating its solution to dryness invariably yield the solid carbonate instead: Ca(HCO₃)₂([[Aqueous solution|aq]]) → CO₂(g) + H₂O(l) + [[Calcium carbonate|CaCO₃]](s). Very few solid bicarbonates other than those of the [[Alkali metal|alkali metals]] and [[ammonium|ammonium ion]] are known to exist.

The above reaction is very important to the formation of [[stalactites]], [[stalagmite]]s, columns, and other [[speleothems]] within [[caves]] and, for that matter, in the formation of the caves themselves. As water containing carbon dioxide (including extra CO₂ acquired from soil organisms) passes through limestone or other calcium carbonate containing minerals, it dissolves part of the calcium carbonate and hence becomes richer in bicarbonate. As the groundwater enters the cave, the excess carbon dioxide is released from the solution of the bicarbonate, causing the much less soluble calcium carbonate to be deposited.

Dissolved carbon dioxide (CO₂) in rainwater (H₂O) reacts with limestone, calcium carbonate (CaCO₃) to form soluble calcium bicarbonate (Ca(HCO₃)₂). This soluble compound is then washed away with the rainwater. This is form of weathering is called 'Carbonation'.

{{Calcium compounds}}

{{DEFAULTSORT:Calcium Bicarbonate}}

[[Category:Bicarbonates]]

[[Category:Acid salts]]

[[Category:Calcium compounds]]

[[Category:Hypothetical chemical compounds]]

[[cs:Hydrogenuhličitan vápenatý]]

[[de:Calciumhydrogencarbonat]]

[[fr:Bicarbonate de calcium]]

[[it:Bicarbonato di calcio]]

[[nl:Calciumwaterstofcarbonaat]]

[[ja:炭酸水素カルシウム]]

[[ru:Гидрокарбонат кальция]]

[[sv:Kalciumvätekarbonat]]

[[th:แคลเซียมไบคาร์บอเนต]]

[[zh:碳酸氫鈣]]

[[pl:Wodorowęglan wapnia]]