Hydrogen fluoride

Hydrogen compounds: hydrogen fluoride

The hydrogen in hydrogen fluoride formally is in the oxidation state 1.

Hydrogen fluoride

• Formula as often written: HF
• Hill system formula: F₁H₁
• CAS registry number: [7664-39-3]
• Formula weight: 20.006
• Class: fluoride

Synonyms

• hydrogen fluoride
• hydrogen(I) fluoride
• hydrofluoric acid

Physical properties

• Colour: colourless
• Appearance: gas
• Melting point: -83.5°C
• Boiling point: 19.5°C
• Density: 1000 kg m^-3 (liquid at 0°C)

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Element analysis

Element percentages for the elements in hydrogen fluoride

Element	%
F	94.96
H	5.04

Synthesis

Dry hydrogen fluoride gas may be made in the laboratory by heating anhydrous potassium hydrogen fluoride and collecting the evolved hydrogen fluoride gas.

KHF₂(s) (500°C) → HF(g) + KF(s)

Hydrogen fluoride gas may be made on very large scales (20000 tonnes par year) by the reaction of calcium(II) fluoirde, CaF₂, with sulphuric acid.

CaF₂(s) + H₂SO₄(l) (200°C) → 2HF(g) + CaSO₄(s)

Solid state structure

• Geometry of hydrogen: 1 coordinate: terminus
• Prototypical structure:

Isotope pattern

What follows is the calculated isotope pattern for the HF unit with the most intense ion set to 100%.

Formula: H₁F₁

mass  %
20 100.0 __________________________________________________
21   0.0 

References

The data on these compounds pages are assembled and adapted from the primary literature and several other sources including the following.

• R.T. Sanderson in Chemical Periodicity, Reinhold, New York, USA, 1960.
• N.N. Greenwood and A. Earnshaw in Chemistry of the Elements, 2nd edition, Butterworth, UK, 1997.
• F.A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann, in Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
• A.F. Trotman-Dickenson, (ed.) in Comprehensive Inorganic Chemistry, Pergamon, Oxford, UK, 1973.
• R.W.G. Wyckoff, in Crystal Structures, volume 1, Interscience, John Wiley & Sons, 1963.
• A.R.West in Basic solid state chemistry Chemistry, John Wiley & Sons, 1999.
• A.F. Wells in Structural inorganic chemistry, 4th edition, Oxford, UK, 1975.
• J.D.H. Donnay, (ed.) in Crystal data determinative tables, ACA monograph number 5, American Crystallographic Association, USA, 1963.
• D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
• J.W. Mellor in A comprehensive treatise on inorganic and theoretical chemistry, volumes 1-16, Longmans, London, UK, 1922-1937.
• J.E. Macintyre (ed.) in Dictionary of inorganic compounds, volumes 1-3, Chapman & Hall, London, UK, 1992.

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Hydrogen	Hydrogène
Wasserstoff	Waterstof
Idrogeno	Hidrógeno
Väte	Hidrogênio