Cobalt(II) fluoride

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Cobalt(II) fluoride
Fluorid kobaltnatý.PNG
IUPAC name Cobalt(II) fluoride
Other names cobalt difluoride
CAS number 10026-17-2
PubChem 24820
EC number 233-061-9
RTECS number GG0770000
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

1217 °C, 1490 K, 2223 °F

Boiling point

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
Crystal structure tetragonal (a,hydrous)
orthorhombic (tetrahydrate)
NFPA 704

NFPA 704.svg

Related compounds
Other anions cobalt(II) oxide, cobalt(II) chloride
Other cations iron(II) fluoride, nickel(II) fluoride
Related compounds cobalt trifluoride
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Cobalt(II) fluoride, also known as cobaltous fluoride, is a chemical compound. Its chemical formula is CoF2. It contains cobalt in its +2 oxidation state. It also contains fluoride ions.

Properties[change | change source]

It is a reddish crystalline solid. It only dissolves a little in water. The hydrate (type with water molecules attached) can dissolve in water. It can dissolve in acid. It can react with hydrogen at 300 °C (572 °F) to make cobalt and hydrogen fluoride.

Preparation[change | change source]

It can be made by reacting anhydrous (without any water molecules attached) cobalt(II) oxide or cobalt(II) chloride with a stream of hydrogen fluoride. This reaction makes the anhydrous form. The hydrated (with water molecules attached) form is made by reacting any cobalt(II) compound with hydrofluoric acid. When fluorine is reacted with cobalt at a high temperature, it makes both cobalt(II) fluoride and cobalt(III) fluoride.

Uses[change | change source]

It is used as a catalyst. It can be used as a source of the fluoride ion in dentist care. It is used in lenses.

Related pages[change | change source]