Potassium hexafluorophosphate

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Potassium hexafluorophosphate
Potassium hexafluorophosphate.png
CAS number 17084-13-8 N
PubChem 23688904
ChemSpider 146640 YesY
Jmol-3D images Image 1
Molecular formula F6KP
Molar mass 184.0625 g/mol
Appearance colourless solid
Density 2.75 g/cm3
Melting point 575 °C (1,067 °F; 848 K)
Solubility in water 8.35g/100 mL (25 °C)[1]
R-phrases R20, R21, R22, R34
S-phrases S26, S27, S36, S37, S39, S45
Main hazards Toxic
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
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

Potassium hexafluorophosphate is the chemical compound with the formula KPF6. This colourless salt consists of potassium cations and hexafluorophosphate anions. It is prepared by the reaction:[2]

PCl5 + KCl + 6 HF → KPF6 + 6 HCl

This exothermic reaction is conducted in liquid hydrogen fluoride. The salt is stable in hot alkaline aqueous solution, from which it can be recrystallized. The sodium and ammonium salts are more soluble in water whereas the rubidium and caesium salts are less so.

KPF6 is a common laboratory source of the hexafluorophosphate anion, a non-coordinating anion that confers lipophilicity to its salts. These salts are often less soluble than the closely related tetrafluoroborates.


  1. ^ Sarmousakis, J. N.; Low, M. J. D. "The Solubility of Potassium Hexafluorophosphate in Water" Journal of the American Chemical Society 1955, 77, 6518. doi:10.1021/ja01629a031
  2. ^ Woyski, M. M.; Shenk, W. J.; Pellon, E. R. (1950). "Hexafluorophosphates of Sodium, Ammonium, and Potassium". Inorg. Synth. Inorganic Syntheses 3: 111–117. doi:10.1002/9780470132340.ch29. ISBN 978-0-470-13234-0.