Cobalt Fluoride 2b4n6l

Cobalt(II) fluoride From Wikipedia, the free encyclopedia

Cobalt(II) fluoride

IUPAC name[hide] Cobalt(II) fluoride

Other names[hide] cobalt difluoride

Identifiers CAS number

10026-17-2

PubChem

24820

ChemSpider

23205

EC number

233-061-9

RTECS number

GG0770000

Jmol-3D images

Image 1 SMILES

[show]

InChI [show]

Properties Molecular formula

CoF2

Molar mass

96.93 g/mol

Appearance

Red crystalline solid

Density

4.46 g/cm3 (anhydrous) 2.22 g/cm3 (tetrahydrate)

Melting point

Boiling point

1217 °C, 1490 K, 2223 °F

1400 °C, 1673 K, 2552 °F

Solubility in water

1.4 g/100 mL (25 °C)

Solubility

soluble in HF insoluble in alcohol, ether,benzene Structure

Crystal structure

tetragonal (a,hydrous) orthorhombic (tetrahydrate) Hazards

NFPA 704

0 3 2 LD50

oral (rat): 150 mg/kg Related compounds

Other anions

cobalt(II) oxide, cobalt(II) chloride

Other cations

iron(II) fluoride, nickel(II) fluoride

Related compounds

cobalt trifluoride

() (what is:

/ ?)

Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references

Cobalt(II) fluoride is a chemical compound with the formula (CoF2). It is a pink crystalline solid [1][2] [3] compound which is antiferromagnetic at low temperatures (T N=37.7 K) 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 CoF2·2H2 O and tri-hydrate CoF2·3H2O forms of the compound. The hydrate will also decompose with heat. Contents [hide]

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1 Preparation

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2 Uses

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3 Analysis

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4 Chemical Properties

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5 References

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6 External links

[edit]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. Other synthesis can occur at higher temperatures. It has been shown that at 500 °C fluorine will combine with cobalt [4] producing a mixture of CoF2 and CoF3. [edit]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. The compound may be used in dental care also used in dental care.

[citation needed]

, since fluoride is

[edit]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 I 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. [edit]Chemical

Properties

CoF2 is a weak Lewis acid. Cobalt(II) complexes are usually octahedral or tetrahedral. As a 19electron 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 °C.