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Names | |
---|---|
IUPAC name
Potassium bifluoride
| |
Other names
Potassium hydrogen difluoride
| |
Identifiers | |
3D model (
JSmol)
|
|
ChemSpider | |
ECHA InfoCard | 100.029.233 |
EC Number |
|
PubChem
CID
|
|
RTECS number |
|
UNII | |
UN number | 1811 |
CompTox Dashboard (
EPA)
|
|
| |
| |
Properties | |
K[HF2 | |
Molar mass | 78.103 g/mol |
Appearance | colourless solid |
Odor | slightly acidic |
Density | 2.37 g/cm3 |
Melting point | 238.7 °C (461.7 °F; 511.8 K) |
Boiling point | decomposes |
| |
Solubility | soluble in ethanol |
Structure | |
monoclinic | |
Thermochemistry | |
Std molar
entropy (S⦵298) |
45.56 J/(mol·K) [1] |
Std enthalpy of
formation (ΔfH⦵298) |
-417.26 kJ/(mol·K) |
Hazards | |
GHS labelling: [2] | |
![]() ![]() | |
Danger | |
H301, H310, H314 | |
P260, P262, P264, P270, P280, P301+P310, P301+P330+P331, P302+P350, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P322, P330, P361, P363, P405, P501 | |
Flash point | non flammable |
Related compounds | |
Other
anions
|
Potassium fluoride |
Other
cations
|
Sodium bifluoride, ammonium bifluoride |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Potassium bifluoride is the inorganic compound with the formula K[HF2. This colourless salt consists of the potassium cation (K+) and the bifluoride anion ([HF2−). The salt is used as an etchant for glass. Sodium bifluoride is related and is also of commercial use as an etchant as well as in cleaning products. [3]
The salt was prepared by Edmond Frémy by treating potassium carbonate or potassium hydroxide with hydrofluoric acid:
With one more equivalent of HF, K[H2F3 (CAS#12178-06-2, m.p. 71.7 C)[ clarification needed] is produced:
Thermal decomposition of K[HF2 gives hydrogen fluoride:
The industrial production of fluorine entails the electrolysis of molten K[HF2 and K[H2F3. [3] The electrolysis of K[HF2 was first used by Henri Moissan in 1886.
![]() | |
![]() | |
Names | |
---|---|
IUPAC name
Potassium bifluoride
| |
Other names
Potassium hydrogen difluoride
| |
Identifiers | |
3D model (
JSmol)
|
|
ChemSpider | |
ECHA InfoCard | 100.029.233 |
EC Number |
|
PubChem
CID
|
|
RTECS number |
|
UNII | |
UN number | 1811 |
CompTox Dashboard (
EPA)
|
|
| |
| |
Properties | |
K[HF2 | |
Molar mass | 78.103 g/mol |
Appearance | colourless solid |
Odor | slightly acidic |
Density | 2.37 g/cm3 |
Melting point | 238.7 °C (461.7 °F; 511.8 K) |
Boiling point | decomposes |
| |
Solubility | soluble in ethanol |
Structure | |
monoclinic | |
Thermochemistry | |
Std molar
entropy (S⦵298) |
45.56 J/(mol·K) [1] |
Std enthalpy of
formation (ΔfH⦵298) |
-417.26 kJ/(mol·K) |
Hazards | |
GHS labelling: [2] | |
![]() ![]() | |
Danger | |
H301, H310, H314 | |
P260, P262, P264, P270, P280, P301+P310, P301+P330+P331, P302+P350, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P322, P330, P361, P363, P405, P501 | |
Flash point | non flammable |
Related compounds | |
Other
anions
|
Potassium fluoride |
Other
cations
|
Sodium bifluoride, ammonium bifluoride |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Potassium bifluoride is the inorganic compound with the formula K[HF2. This colourless salt consists of the potassium cation (K+) and the bifluoride anion ([HF2−). The salt is used as an etchant for glass. Sodium bifluoride is related and is also of commercial use as an etchant as well as in cleaning products. [3]
The salt was prepared by Edmond Frémy by treating potassium carbonate or potassium hydroxide with hydrofluoric acid:
With one more equivalent of HF, K[H2F3 (CAS#12178-06-2, m.p. 71.7 C)[ clarification needed] is produced:
Thermal decomposition of K[HF2 gives hydrogen fluoride:
The industrial production of fluorine entails the electrolysis of molten K[HF2 and K[H2F3. [3] The electrolysis of K[HF2 was first used by Henri Moissan in 1886.