Cobalt(II) carbonate: Difference between revisions

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 431006470

| ImageFile =

| ImageFile1 = Calcium-carbonate-xtal-3D-SF.png

| ImageFile2 = Cobalt(2) carbonate.jpg

| ImageSize1 = 180px

| ImageName2 = Cobalt(II) carbonate powder

| SystematicName =

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 513-79-1

| CASNo2_Ref = {{cascite|correct|CAS}}

| CASNo2 = 12602-23-2

| CASNo2_Comment = (cobalt carbonate hydroxide)

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 7H73A68FUV

| UNII2_Ref = {{fdacite|correct|FDA}}

| UNII2 = W58TNI7T29

| UNII2_Comment = (cobalt carbonate hydroxide)

| PubChem = 10565

| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}

| ChemSpiderID = 10123

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

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

| InChIKey = ZOTKGJBKKKVBJZ-NUQVWONBAB

| StdInChI_Ref = {{stdinchicite|changed|chemspider}}

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

| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}

| StdInChIKey = ZOTKGJBKKKVBJZ-UHFFFAOYSA-L

| RTECS =

| Formula = CoCO₃

| Appearance = pink solid

| MolarMass = 118.941 g/mol

| Density = 4.13 g/cm³

| MeltingPtC = 427

| MeltingPt_notes = <ref name=chemister /><br> decomposes before melting to [[cobalt(II) oxide]] (anhydrous)<br> {{convert|140|C|F K}}<br> decomposes (hexahydrate)

| BoilingPt =

| Solubility = 0.000142 g/100 mL (20 °C)<ref name="crc97">{{cite book |editor1-last=Haynes |editor1-first=W.M. |title=CRC Handbook of Chemistry and Physics |date=2017 |publisher=CRC Press, Taylor & Francis Group |isbn=978-1-4987-5429-3 |pages=4–58 |edition=97th |language=en}}</ref>

| SolubleOther = soluble in acid <br> negligible in [[Alcohol (chemistry)|alcohol]], [[methyl acetate]] <br> insoluble in [[ethanol]]

| SolubilityProduct = 1.0·10⁻¹⁰<ref>{{cite web |url=http://www.ktf-split.hr/periodni/en/abc/kpt.html |title=Solubility product constants |accessdate=2012-05-17 |url-status=dead |archiveurl=https://web.archive.org/web/20120615020049/http://www.ktf-split.hr/periodni/en/abc/kpt.html |archivedate=2012-06-15 }}</ref>

| RefractIndex = 1.855

| CrystalStruct = Rhombohedral (anhydrous) <br> Trigonal (hexahydrate)

}}

| Section4 = {{Chembox Thermochemistry

| DeltaHf = −722.6 kJ/mol<ref name=chemister>{{Cite web|url=http://chemister.ru/Database/properties-en.php?dbid=1&id=573|title=Cobalt(II) carbonate}}</ref>

| Entropy = 79.9 J/mol·K<ref name=chemister />

| DeltaGf = -651 kJ/mol<ref name=chemister />

}}

| Section5 =

| Section6 =

| MainHazards =

| GHSPictograms = {{GHS07}}{{GHS08}}<ref name="sigma">{{Sigma-Aldrich|id=379956|name=Cobalt(II) carbonate|accessdate=2014-05-06}}</ref>

| GHSSignalWord = Warning

| HPhrases = {{H-phrases|302|315|317|319|335|351}}<ref name="sigma" />

| PPhrases = {{P-phrases|261|280|305+351+338}}<ref name="sigma" />

| FlashPt =

| AutoignitionPt =

| LD50 = 640 mg/kg (oral, rats)

| NFPA-H = 2

| NFPA-F = 0

| NFPA-R = 0

'''Cobalt(II) carbonate''' is the [[inorganic compound]] with the formula CoCO₃. This pink paramagnetic solid is an intermediate in the [[hydrometallurgy|hydrometallurgical purification]] of cobalt from its ores. It is an inorganic pigment, and a precursor to [[catalyst]]s.<ref name=Ull>{{Ullmann|doi=10.1002/14356007.a07_281.pub2| title=Cobalt and Cobalt Compounds | year=2005 | last1=Donaldson | first1=John Dallas | last2=Beyersmann | first2=Detmar | isbn=3527306730 }}</ref> Cobalt(II) carbonate also occurs as the rare red/pink mineral [[spherocobaltite]].<ref name="mindat">{{cite web |title=Spherocobaltite: Spherocobaltite mineral information and data |url=http://www.mindat.org/min-3726.html |website=www.mindat.org |accessdate=7 August 2018 |ref=mindat}}</ref>

==Preparation and structure==

It is prepared by combining solutions cobaltous sulfate and [[sodium bicarbonate]]:

:CoSO₄ + 2 NaHCO₃ → CoCO₃ + Na₂SO₄ + H₂O + CO₂

This reaction is used in the precipitation of cobalt from an extract of its roasted ores.<ref name=Ull/>

CoCO₃ adopts a structure like [[calcite]], consisting of cobalt in an [[octahedral coordination geometry]].<ref>{{cite journal|title=Structures of hydrothermally synthesized cobalt(II) carbonate and nickel(II) carbonate|author=Pertlik, F.|journal=Acta Crystallographica Section C|year=1986|volume=42|pages=4–5|doi=10.1107/S0108270186097524}}</ref>

==Reactions==

Like most transition metal carbonates, cobalt carbonate is insoluble in water, but is readily attacked by mineral acids:

:CoCO₃ + 2 HCl + 5 H₂O → [Co(H₂O)₆]Cl₂ + CO₂

It is used to prepare many coordination complexes. The reaction of cobalt(II) carbonate and [[acetylacetone]] in the presence of [[hydrogen peroxide]] gives [[tris(acetylacetonato)cobalt(III)]].<ref>{{cite book|doi=10.1002/9780470132364.ch53|chapter=Cobalt(III) Acetylacetonate|title=Inorganic Syntheses|year=1957|last1=Bryant|first1=Burl E.|last2=Fernelius|first2=W. Conard|pages=188–189|isbn=9780470132364}}</ref>

Heating the carbonate proceeds in a typical way for [[calcining]], except that the product becomes partially oxidized:

: 6{{nbsp}}CoCO₃ + O₂ → 2{{nbsp}}Co₃O₄ + 6{{nbsp}}CO₂

The resulting [[Cobalt(II,III) oxide|Co₃O₄]] converts reversibly to [[CoO]] at high temperatures.<ref>G.A. El-Shobaky, A.S. Ahmad, A.N. Al-Noaimi and H.G. El-Shobaky Journal of Thermal Analysis and Calorimetry 1996, Volume 46, Number 6 , pp.1801-1808. [https://doi.org/10.1007%2FBF01980784 online abstract]</ref>

==Uses==

Cobalt carbonate is a precursor to [[cobalt carbonyl]] and various cobalt salts. It is a component of [[dietary supplement]]s since cobalt is an [[essential element]]. It is a precursor to blue pottery glazes, famously in the case of [[Delftware]].

==Related compounds==

At least two cobalt(II) carbonate-hydroxides are known: Co₂(CO₃)(OH)₂ and Co₆(CO₃)₂(OH)₈·H₂O.<ref>{{cite journal |doi=10.1107/S2053229618017734| title=A Quarter of a Century After its Synthesis and with >200 Papers Based on its Use, 'Co(CO₃)_0.5(OH)_0.11H₂O′ Proves to be Co₆(CO₃)₂(OH)₈·H₂O from Synchrotron Powder Diffraction Data | year=2019 | last1=Bhojane | first1=Prateek | last2=Le Bail | first2=Armel | last3=Shirage | first3=Parasharam M. | journal=Acta Crystallographica Section C: Structural Chemistry | volume=75 | issue=Pt 1 | pages=61–64 | pmid=30601132 | s2cid=58657483 | url=https://zenodo.org/record/3755496 }}</ref>

The moderately rare [[spherocobaltite]] is a natural form of cobalt carbonate, with good specimens coming especially from the [[Republic of Congo]]. "Cobaltocalcite" is a cobaltiferous [[calcite]] variety that is quite similar in [[Crystal habit|habit]] to spherocobaltite.<ref name="mindat" />

Toxicity has rarely been observed. Animals, including humans, require trace amounts of cobalt, a component of [[vitamin B12]].<ref name=Ull/>

==External links==

* {{Commons category-inline|Cobalt(II) carbonate}}

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{{Carbonates}}

[[Category:Cobalt(II) compounds]]