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. All known hydrogen halides are gases at standard temperature and pressure.
| Compound | Chemical formula | Bond length d(H−X) / pm (gas phase) | model | Dipole μ / D | Aqueous phase (acid) | Aqueous Phase pKa 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 | ||
| hydrogen astatide astatine hydride (astatane) | HAt | −0.06 | hydroastatic acid | ? | ||
| hydrogen tennesside tennessine hydride (tennessane) | HTs | −0.24 ? | hydrotennessic acid | ? | ||
