Hydrogen halide

Hydrogen halides, are chemical compounds which are formed from the corresponding halogen with hydrogen. General chemical formula HX, wherein X is the halogen. Their aqueous solutions are called hydrogen halides. However, the common name for hydrochloric acid hydrochloric acid and hydrofluoric acid to hydrofluoric acid are much more familiar.

  • 2.1 Astatwasserstoff

Properties

Physical Properties

Besides hydrofluoric all hydrogen halides are colorless, pungent-smelling gases under standard conditions. Your boiling and melting temperatures increase with increasing atomic number of the halogen. One exception is the hydrogen fluoride, which is significantly different due to strong intermolecular interactions by hydrogen bonds of this tendency. While hydrogen fluoride itself still occurs in the gaseous state as a hexamer, all other hydrogen halides are monomeric. The enthalpies of the HX bond rise, bond lengths decrease with decreasing atomic number.

Chemical Properties

Hydrogen halides are classic Brønsted acids: They dissociate in aqueous solution in the halide anions (X- ) and protons; latter are present as hydrated oxonium cations ( H3O ), but are usually simplified with H denotes. The pKa values ​​of the hydrogen halides fall with increasing period of the halogen from strong, with you has made a particularly strong jump between the hydrochloric and hydrofluoric acid. The latter is only a weak acid. Thus, the acid strength increases with decreasing dissociation, and would not be as expected, with the increasing electronegativity of the halogen. Another noticeable trend is the increase in the reducing power of hydrogen halides and acids with increasing atomic number. Iodide (acid ) is used, in fact, as a reducing agent. Respond to hydrogen halides, hydrogen halides with amines.

Specific hydrogen halides

More detailed information about the properties, use, safety instructions etc. - except for astatine derivative - to see the specific hydrogen halides or acids:

  • Hydrogen fluoride reacts with water to hydrofluoric acid ( hydrofluoric acid )
  • Hydrogen chloride reacts with water to hydrochloric acid ( hydrochloric acid)
  • Hydrogen bromide reacts with water to hydrobromic
  • Hydrogen iodide reacts with water to hydroiodic

Astatwasserstoff

Astatine occurs as radioactive, since very short-lived intermediate member of decay series, and is found in nature thus only in vanishingly small amounts. According to almost the level of knowledge about the chemical and physical properties of astatine and consequently the Astatwasserstoffs. It is only known that the reducing power of the latter is greater than that of hydrogen iodide, which the group trend as anticipated.

Mineral hydration
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