Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Cobalt(II) fluoride: Difference between pages

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| Verifiedfields = changed

| verifiedrevid = 476995955

|Section1={{Chembox Identifiers

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

| CASNo_Ref = {{cascite|changed|??}}

| CASNo = 10026-17-2

| UNII_Ref = {{fdacite|changed|FDA}}

| UNII =9KI67810UR

|Section2={{Chembox Properties

| Formula = [[Cobalt|Co]][[Fluorine|F₂]]

| MolarMass = 96.93 g/mol

| Appearance = Red crystalline solid

| Density = 4.46 g/cm³ (anhydrous) <br> 2.22 g/cm³ (tetrahydrate)

| MeltingPtC = 1217

| BoilingPtC = 1400

| Solubility = 1.4 g/100 mL (25 °C)

| SolubleOther = soluble in [[hydrofluoric acid|HF]] <br> insoluble in [[ethanol|alcohol]], [[diethyl ether|ether]], [[benzene]]

| MagSus = +9490.0·10⁻⁶ cm³/mol

|Section3={{Chembox Structure

| CrystalStruct = tetragonal (anhydrous) <br> orthorhombic (tetrahydrate)

|Section4={{Chembox Hazards

| MainHazards =

| LD50 = oral (rat): 150 mg/kg

| NFPA-H = 3

| NFPA-F = 0

| NFPA-R = 0

| NFPA-S =

| FlashPt =

| AutoignitionPt =

|Section5={{Chembox Related

| OtherAnions = [[cobalt(II) oxide]], [[cobalt(II) chloride]]

| OtherCations = [[iron(II) fluoride]], [[nickel(II) fluoride]]

| OtherCompounds = [[cobalt trifluoride]] }}

[[File:Фторид кобальта.jpg|alt=Anhydrous cobalt(II) fluoride|thumb|Anhydrous cobalt(II) fluoride]]

'''Cobalt(II) fluoride''' is a [[chemical compound]] with the formula (CoF₂). It is a pink crystalline solid compound<ref>{{citation|title=Handbook of Inorganic Chemicals |author= Pradyot Patnaik|year= 2002|publisher=McGraw-Hill Professional|url= https://books.google.com/books?id=Xqj-TTzkvTEC&q=%22Cobalt(II)+fluoride%22&pg=PA241|isbn=978-0-07-049439-8}}</ref><ref>{{citation |title=Article title Heat Exchange between Cobalt(II) Fluoride Powder and the Wall of Rotating Cylinder |author1=Pashkevich, D. S. |author2=Radchenko S. M. |author3=Mukhortov, D. A. |journal=Russian Journal of Applied Chemistry |publisher=Consultants Bureau |url=http://www.maik.rssi.ru/abstract/rjapchem/97/rjapchem1447_abstract.pdf |issn=1070-4272 |access-date=2007-03-07 |archive-url=https://web.archive.org/web/20040929065300/http://www.maik.rssi.ru/abstract/rjapchem/97/rjapchem1447_abstract.pdf |archive-date=2004-09-29 |url-status=dead }}</ref> which is [[Antiferromagnetism|antiferromagnetic]] at low temperatures (T_N=37.7 K)<ref>Ashcroft/Mermin: Solid State Physics (Tab. 33.2)</ref> The formula is given for both the red tetragonal crystal, (CoF₂), and the tetrahydrate red orthogonal crystal, (CoF₂·4H₂O). CoF₂ is used in oxygen-sensitive fields, namely metal production. In low concentrations, it has public health uses.

CoF₂ is sparingly soluble in water. The compound can be dissolved in warm [[mineral acid]], and will decompose in boiling water. Yet the hydrate is water-soluble, especially the di-hydrate CoF₂·2H₂O and tri-hydrate CoF₂·3H₂O forms of the compound. The hydrate will also decompose with heat.

Like some other metal difluorides, CoF₂ crystallizes in the [[rutile]] structure, which features octahedral Co centers and planar fluorides.<ref>{{cite journal |doi=10.1021/ja01650a005|title=The Crystal Structure of MnF₂, FeF₂, CoF₂, NiF₂ and ZnF₂|first1=J. W.|last1=Stout|first2=Stanley A.|last2=Reed|journal= J. Am. Chem. Soc.|year=1954|volume=76|issue=21|pages=5279–5281}}</ref>

==Preparation==

Cobalt(II) fluoride can be prepared from anhydrous cobalt(II) chloride or cobalt(II) oxide in a stream of [[hydrogen fluoride]]:

:CoCl₂ + 2HF → CoF₂ + 2HCl

:CoO + 2HF → CoF₂ + H₂O

It is produced in the reaction of cobalt (III) fluoride with water.

The [[tetrahydrate]] cobalt(II) fluoride is formed by dissolving cobalt(II) in hydrofluoric acid. The anhydrous fluoride can be extracted from this by [[Dehydration reaction|dehydration]]. Other synthesis can occur at higher temperatures. It has been shown that at 500&nbsp;°C [[fluorine]] will combine with cobalt producing a mixture of CoF₂ and CoF₃.<ref>{{citation|title= Comprehensive Inorganic Chemistry |author= J.C. Bailar |year= 1973|publisher=Pergoamon}}</ref>

==Uses==

Cobalt(II) fluoride can be used as a catalyst to alloy metals. It is also used for optical deposition, of which it tremendously improves optical quality. Cobalt(II) fluoride is available in most volumes in an ultra high purity composition. High purity compositions improve optical qualities and its usefulness as a standard.

==Analysis==

To analyze this compound, Cobalt (II) fluoride can be dissolved in nitric acid. The solution is then diluted with water until appropriate concentration for AA or ICP [[spectrophotometry]] for the cobalt. A small amount of salt can be dissolved in cold water and analyzed for fluoride ion by a fluoride ion-selective electrode or ion [[chromatography]].

==Chemical properties==

CoF₂ is a weak [[Lewis acid]]. Cobalt(II) complexes are usually octahedral or tetrahedral. As a 19-electron species it is a good reducing agent, fairly oxidizable into an 18-electron compound. Cobalt(II) fluoride can be reduced by hydrogen at a 300&nbsp;°C.

==References==

<references/>

==External links==

{{Commons category|Cobalt(II) fluoride}}

* [https://web.archive.org/web/20060219230038/http://www.npi.gov.au/database/substance-info/profiles/26.html National Pollutant Inventory - Cobalt fact sheet]

*[https://web.archive.org/web/20060116134617/http://www.npi.gov.au/database/substance-info/profiles/44.html National Pollutant Inventory - Fluoride and compounds fact sheet]

*[http://www.americanelements.com/cof.html]

{{Cobalt compounds}}

{{fluorides}}

[[Category:Fluorides]]

[[Category:Metal halides]]

[[Category:Cobalt(II) compounds]]