Hydrogen halide

In chemistry, hydrogen halides (hydrohalic acids when in the aqueous phase) are diatomic, inorganic compounds that function as Arrhenius acids. The formula is HX where X is one of the halogens: fluorine, chlorine, bromine, iodine, astatine, or tennessine.^[1] All known hydrogen halides are gases at standard temperature and pressure.^[2]

Compound	Chemical formula	Dipole μ / D	Aqueous phase (acid)	Aqueous Phase pK_a values
hydrogen fluoride (fluorane)	HF	1.86	hydrofluoric acid	3.1
hydrogen chloride (chlorane)	HCl	1.11	hydrochloric acid	-3.9
hydrogen bromide (bromane)	HBr	0.788	hydrobromic acid	-5.8
hydrogen iodide (iodane)	HI	0.382	hydroiodic acid	-10.4 ^[3]
hydrogen astatide astatine hydride (astatane)	HAt	−0.06	hydroastatic acid	?
hydrogen tennesside tennessine hydride (tennessane)	HTs	−0.24 ?	hydrotennessic acid	? ^[4]

^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
^ The Acidity of the Hydrogen Halides. (2020, August 21). Retrieved May 5, 2021, from https://chem.libretexts.org/@go/page/3699
^ Schmid, Roland; Miah, Arzu M. (2001). "The Strength of the Hydrohalic Acids". Journal of Chemical Education. 78 (1). American Chemical Society (ACS): 116. doi:10.1021/ed078p116. ISSN 0021-9584.
^ de Farias, Robson Fernandes (January 2017). "Estimation of some physical properties for tennessine and tennessine hydride (TsH)". Chemical Physics Letters. 667: 1–3. Bibcode:2017CPL...667....1D. doi:10.1016/j.cplett.2016.11.023.