Hydrogen fluoride

Not to be confused with the element hafnium, symbol Hf.
Hydrogen fluoride
Names
Other names
Fluorane
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.028.759 Edit this at Wikidata
KEGG
RTECS number
  • MW7875000
UNII
UN number 1052
  • InChI=1S/FH/h1H checkY
    Key: KRHYYFGTRYWZRS-UHFFFAOYSA-N checkY
  • InChI=1/FH/h1H
    Key: KRHYYFGTRYWZRS-UHFFFAOYAC
  • F
Properties
HF
Molar mass 20.006 g·mol−1
Appearance colourless gas or colourless liquid (below 19.5 °C)
Odor unpleasant
Density 1.15 g/L, gas (25 °C)
0.99 g/mL, liquid (19.5 °C)
1.663 g/mL, solid (–125 °C)
Melting point −83.6 °C (−118.5 °F; 189.6 K)
Boiling point 19.5 °C (67.1 °F; 292.6 K)
miscible (liquid)
Vapor pressure 783 mmHg (20 °C)[1]
Acidity (pKa) 3.17 (in water),

15 (in DMSO) [2]

Conjugate acid Fluoronium
Conjugate base Fluoride
1.00001
Structure
Linear
1.86 D
Thermochemistry
8.687 J/g K (gas)
−13.66 kJ/g (gas)
−14.99 kJ/g (liquid)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Highly toxic, corrosive, irritant
GHS labelling:
GHS05: Corrosive GHS06: ToxicGHS07: Exclamation mark
Danger
H300+H310+H330, H314
P260, P262, P264, P270, P271, P280, P284, P301+P310, P301+P330+P331, P302+P350, P303+P361+P353, P304+P340, P305+P351+P338, P310, P320, P321, P322, P330, P361, P363, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazard POI: Poisonous
4
0
1
POI
Flash point none
Lethal dose or concentration (LD, LC):
17 ppm (rat, oral)
1276 ppm (rat, 1 hr)
1774 ppm (monkey, 1 hr)
4327 ppm (guinea pig, 15 min)[3]
313 ppm (rabbit, 7 hr)[3]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 3 ppm[1]
REL (Recommended)
 TWA 3 ppm (2.5 mg/m3) C 6 ppm (5 mg/m3) [15-minute][1]
IDLH (Immediate danger)
 30 ppm[1]
Related compounds
Other anions
 Hydrogen chloride
Hydrogen bromide
Hydrogen iodide
Hydrogen astatide
Other cations
 Sodium fluoride
Potassium fluoride
Rubidium fluoride
Caesium fluoride
Related compounds
 Water
Ammonia
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Hydrogen fluoride (fluorane) is an inorganic compound with chemical formula HF. It is a very poisonous, colorless gas or liquid that dissolves in water to yield hydrofluoric acid. It is the principal industrial source of fluorine, often in the form of hydrofluoric acid, and is an important feedstock in the preparation of many important compounds including pharmaceuticals and polymers such as polytetrafluoroethylene (PTFE). HF is also widely used in the petrochemical industry as a component of superacids. Due to strong and extensive hydrogen bonding, it boils at near room temperature, which is much higher of a temperature than other hydrogen halides.

Hydrogen fluoride is an extremely dangerous gas, forming corrosive and penetrating hydrofluoric acid upon contact with moisture. The gas can also cause blindness by rapid destruction of the corneas.

  1. ^ a b c d NIOSH Pocket Guide to Chemical Hazards. "#0334". National Institute for Occupational Safety and Health (NIOSH).
  2. ^ Evans, D. A. "pKa's of Inorganic and Oxo-Acids" (PDF). Retrieved June 19, 2020.
  3. ^ a b "Hydrogen fluoride". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).