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 an aqueous solution termed 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, e.g. 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, much higher 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.
Hydrogen fluoride info:
Names | |
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Other names
Fluorane
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Identifiers | |
ChemSpider | |
KEGG | |
PubChem CID
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RTECS number |
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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) |
completely 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 |
Refractive index (nD)
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1.00001 |
Structure | |
Linear | |
1.86 D | |
Thermochemistry | |
Std molar
entropy (S⦵298) |
8.687 J/g K (gas) |
Std enthalpy of
formation (ΔfH⦵298) |
−13.66 kJ/g (gas) −14.99 kJ/g (liquid) |