Potassium hexafluorophosphate

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Potassium hexafluorophosphate
IUPAC name Potassium hexafluorophosphate
Identifiers
CAS number [17084-13-8]
Properties
Molecular formula F6KP
Molar mass 184.06
Appearance colourless solid
Density 2.75 g/mL
Melting point

575 °C

Solubility in water 0.432M (25 °C)
Hazards
Main hazards toxic
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and 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: [1]

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, used to confer lipophilicity to certain salts.

[edit] References

  1. ^ Woyski, M. M. “Hexafluorophosphates of Sodium, Ammonium, and Potassium” Inorganic Syntheses volume III, pp. 111-117.