Hexafluorophosphoric acid

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Hexafluorophosphoric acid[1]
Identifiers
CAS number 16940-81-1 YesY
PubChem 16211447
ChemSpider 17339451 N
EC number 241-006-5
Jmol-3D images Image 1
Properties
Molecular formula HPF6
Molar mass 145.972 g/mol
Appearance colorless oily liquid
Melting point decomposes at 25°C
Solubility in water reacts
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Hexafluorophosphoric acid is the chemical compound with the chemical formula H3OPF6. This strong Brønsted acid features a non-coordinating anion, hexafluorophosphate (PF
6
). It is formed from the reaction of hydrogen fluoride with phosphorus pentafluoride.[2]

Like many strong acids, hexafluorophosphoric acid is not isolable but is handled only in solution. Its aqueous solutions consist of hydronium ion, H
3
O+
, and PF
6
. Additionally, such solutions contain products derived from hydrolysis of the P-F bonds, including HPO
2
F
2
, H
2
PO
2
F
, and H
3
PO
4
, and their conjugate bases.[3] Hexafluorophosphoric acid is known to vigorously attack glass, and decomposes to generate HF.

"Crystalline HPF
6
" has been obtained as the hexahydrate, wherein PF
6
is enclosed in truncated octahedral cages defined by the water and protons. NMR spectroscopy indicates that solutions derived from this hexahydrate contain significant amounts of HF.[3]

See also[edit]

References[edit]

  1. ^ Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, FL: CRC Press. pp. 4–74. ISBN 0-8493-0594-2. 
  2. ^ Arpad Molnar; G. K. Surya Prakash; Jean Sommer (2009). Superacid Chemistry (2nd ed.). Wiley-Interscience. p. 44. ISBN 0-471-59668-X. 
  3. ^ a b D. W. Davidson; S. K. Garg (May 1972). "The Hydrate of Hexafluorophosphoric Acid". Canadian Journal of Chemistry 50: 3515–3520. doi:10.1139/v72-565.