Hydrogen compounds: hydrogen fluoride
The hydrogen in hydrogen fluoride formally is in the oxidation state 1.
- Formula as often written: HF
- Hill system formula: F1H1
- CAS registry number: [7664-39-3]
- Formula weight: 20.006
- Class: fluoride
- hydrogen fluoride
- hydrogen(I) fluoride
- hydrofluoric acid
- Colour: colourless
- Appearance: gas
- Melting point: -83.5°C
- Boiling point: 19.5°C
- Density: 1000 kg m-3 (liquid at 0°C)
Element percentages for the elements in hydrogen fluoride
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:
What follows is the calculated isotope pattern for the HF unit with the most intense ion set to 100%.
20 100.0 __________________________________________________
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.