Zinc fluoride

Zinc fluoride
Other names

Zinc difluoride
Identifiers
CAS number 7783-49-5 Y, 
13986-18-0 (tetrahydrate)
PubChem 24551
ChemSpider 22957 Y
RTECS number ZH3200000
Jmol-3D images Image 1
Properties
Molecular formula ZnF2
Molar mass 103.406 g/mol (anhydrous)
175.45 g/mol (tetrahydrate)
Appearance white needles
hygroscopic
Density 4.95 g/cm3 (anhydrous)
2.30 g/cm3 (tetrahydrate)
Melting point

872 °C (anhydrous)
100 °C, decomp (tetrahydrate)
Boiling point

1500 °C (anhydrous)
Solubility in water .000052 g/100 mL (anhydrous)
1.52 g/100 mL, 20 °C (tetrahydrate)
Solubility sparingly soluble in HCl, HNO3, ammonia
Structure
Crystal structure tetragonal (anhydrous), tP6
Space group P42/mnm, No. 136
Hazards
EU Index Not listed
NFPA 704
0
2
1
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Zinc fluoride (ZnF2) is an inorganic chemical compound. It is encountered as the anydrous form and also as the tetrahydrate, ZnF2.4H2O (rhombohedral crystal structure). [1] It has a high melting point and has the rutile structure containing 6 coordinate zinc, which suggests appreciable ionic character in its chemical bonding.[2] Unlike the other zinc halides, ZnCl2, ZnBr2 and ZnI2, it is not very soluble in water.[2]

Preparation and reactions

Zinc fluoride can be synthesized several ways.

  1. Reaction of a fluoride salt with zinc chloride, to yield zinc fluoride and a chloride salt, in aqueous solution.
  2. The reaction of zinc metal with fluorine gas.[2]
  3. Reaction of hydrofluoric acid with zinc, to yield hydrogen gas (H2) and zinc fluoride (ZnF2).[2]

Zinc fluoride can be hydrolysed by hot water to form the zinc hydroxyfluoride, Zn(OH)F.[3]

References

  1. ^ Dale L. Perry, Sidney L. Phillips, 1995, Handbook of Inorganic Compounds, CRC Press, ISBN 0-8493-8671-3
  2. ^ a b c d Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. ISBN 0080379419. 
  3. ^ Studies on metal hydroxy compounds. I. Thermal analyses of zinc derivatives ε-Zn(0H)2, Zn5(OH)8C12.H20, β- ZnOHC1, and ZnOHF, K SRIVASTAVA, EA SECCO - Canadian Journal of Chemistry, 1967 579-583

External links