:Cobalt(II) oxide
{{redirect|CoO||COO (disambiguation)}}
{{chembox
| Watchedfields = changed
| verifiedrevid = 441022830
| Name = Cobalt(II) oxide
| ImageFile = Cobalt(II)-oxide-3D-vdW.png
| ImageName = Cobalt(II) oxide
| IUPACName = Cobalt(II) oxide
| OtherNames = Cobaltous oxide
Cobalt monoxide
| SystematicName =
| Section1 = {{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 8117730
| InChI = 1/Co.O/rCoO/c1-2
| SMILES = [Co]=O
| InChIKey = IVMYJDGYRUAWML-NNYFCMOLAO
| InChI1 = 1/Co.O/q+2;-2
| InChIKey1 = IUYLTEAJCNAMJK-UHFFFAOYAY
| SMILES1 = [Co+2].[O-2]
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/Co.O/q+2;-2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = IUYLTEAJCNAMJK-UHFFFAOYSA-N
| CASNo = 1307-96-6
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = V9X9644V7Q
| PubChem = 9942118
| RTECS = GG2800000
| UNNumber = 3288
| EINECS = 215-154-6
}}
| Section2 = {{Chembox Properties
| Formula = CoO
| MolarMass = 74.9326 g/mol
| Appearance = olive or gray powder
| Odor = odorless
| Density = 6.45 g/cm3 {{RubberBible87th}}
| Solubility = insoluble in water[http://www.alfa.com/content/msds/german/44354.pdf Advanced Search – Alfa Aesar – A Johnson Matthey Company] {{Webarchive|url=https://web.archive.org/web/20110719172732/http://www.alfa.com/content/msds/german/44354.pdf |date=2011-07-19 }}. Alfa.com. Retrieved on 2011-11-19.
| MeltingPtC = 1933
| BoilingPt =
| MagSus = +4900.0·10−6 cm3/mol
}}
| Section3 = {{Chembox Structure
| SpaceGroup = Fm3m, No. 225
}}
| Section4 =
| Section5 =
| Section6 =
| Section7 = {{Chembox Hazards
| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics1551.htm ICSC 1551]
| MainHazards =
| GHSPictograms = {{GHS07}}{{GHS09}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|302|317|410}}
| PPhrases = {{P-phrases|260|280|284|301+310+330|304+340+310|342+311|403+233}}
| NFPA-H = 3
| NFPA-F = 0
| NFPA-R = 0
| FlashPt = Non-flammable
| LD50 = 202 mg/kg
}}
| Section8 = {{Chembox Related
| OtherAnions = Cobalt(II) sulfide
Cobalt(II) hydroxide
| OtherCations = Iron(II) oxide
Nickel(II) oxide
| OtherCompounds = Cobalt(II,III) oxide
Cobalt(III) oxide
}}
}}
Cobalt(II) oxide is an inorganic compound that has been described as an olive-green or gray solid. It is used extensively in the ceramics industry as an additive to create blue-colored glazes and enamels, as well as in the chemical industry for producing cobalt(II) salts. A related material is cobalt(II,III) oxide, a black solid with the formula Co3O4.
Structure and properties
CoO crystals adopt the periclase (rock salt) structure with a lattice constant of 4.2615 Å.{{cite journal|doi=10.1103/PhysRevB.35.6847|title=Percolation effects and magnetic properties of the randomly diluted fcc system CopMg1-pO|year=1987|author1=Kannan, R. |author2=Seehra, Mohindar S. |journal=Physical Review B|volume=35|pages=6847–6853|issue=13|pmid=9940938 |bibcode=1987PhRvB..35.6847K }}
It is antiferromagnetic below 289 K.{{cite journal|doi=10.1103/PhysRevB.24.419|title=Principal magnetic susceptibilities and uniaxial stress experiments in CoO|year=1981|author1=Silinsky, P. S. |author2=Seehra, Mohindar S. |journal=Physical Review B|volume=24|issue=1 |pages=419–423|bibcode=1981PhRvB..24..419S }}
Preparation
Cobalt(II) oxide is prepared by oxidation of cobalt powder with air or by thermal decomposition of cobalt(II) nitrate or the carbonate.{{Greenwood&Earnshaw2nd}}{{Ullmann |doi=10.1002/14356007.a07_281.pub2|title=Cobalt and Cobalt Compounds|year=2005|last1=Donaldson|first1=John Dallas|last2=Beyersmann|first2=Detmar}}
Cobalt(II,III) oxide decomposes to cobalt(II) oxide at 950 °C:{{cite patent | title = Process for making a cobalt oxide catalyst | invent1 = James, Leonard E. | invent2 = Crescentini, Lamberto | invent3 = Fisher, William B. | pubdate = 1983-06-21 | number = 4389339 | country = US }}
:2 Co3O4 → 6 CoO + O2
It may also be prepared by precipitating the hydroxide, followed by thermal dehydration:{{cn|date=March 2021}}
: CoX2 + 2 KOH → Co(OH)2 + 2 KX
: Co(OH)2 → CoO + H2O
Reactions
As can be expected, cobalt(II) oxide reacts with mineral acids to form the corresponding cobalt salts:{{cn|date=March 2021}}
: CoO + 2 HX → CoX2 + H2O
Applications
Cobalt(II) oxide has for centuries been used as a coloring agent on kiln fired pottery. The additive provides a deep shade of blue named cobalt blue. The band gap (CoO) is around 2.4 eV.{{Citation Needed|date=October 2017}}
It also is used in cobalt blue glass.