Chlorides are compounds of the chemical element chlorine . This can be combined with metals , semimetals or non-metals . Metal chlorides such as B. Sodium and cobalt (II) chloride are salts of hydrochloric acid, better known as hydrochloric acid ( chemical formula : HCl). Such a chloride simply contains negatively charged chlorine (−I) ions Cl - (usually called chloride ions) in its ion lattice . Non-metal chlorides such as hydrogen chloride , sulfur chlorides , carbon tetrachloride ( carbon tetrachloride ) and chlorine dioxide are molecular compounds that are much more volatile than salt-like chlorides. Chlorinated hydrocarbons are used in the organic material as derivatives of various compounds considered the hydrocarbons and named. Thus, methane , in which a hydrogen atom replaced by a chlorine atom ( substituted ) was chloromethane or methylene chloride mentioned. Here, however, as with the ionic compounds mentioned above, chlorine is not present as a chloride ion, but is covalently bonded to the carbon atom . In the real sense, however, chloride is only the abbreviation for the single negatively charged chloride ion. Organic amines form organic hydrochlorides with hydrogen chloride , which contain chloride ions.
Chlorides occur naturally in large deposits , e.g. B. sodium chloride as rock salt or halite , potassium chloride as sylvin , carnallite , kainite and sylvinite , magnesium chloride as bishopite . Most of the chlorides are found dissolved in sea water and in large underground salt deposits , which were created by the evaporation of the water in primeval oceans .
For the wet chemical qualitative detection of chloride, a solution is first prepared. Soda extract is advantageous because numerous interfering cations are separated off in its filtrate . Halide tests can then be carried out. Chlorides are precipitated as white, water-insoluble silver chloride with silver nitrate solution .
Chloride resulting from the redox reaction of metals with elemental chlorine or with hydrochloric acid only if they are in the voltage range below the hydrogen are as hydrochloric acid not oxidizing effect. But they also arise in the reaction of hydroxides , metal oxides , carbonates , hydrogen carbonates and, in general, of salts of weaker acids with hydrochloric acid.
Chlorides can be obtained by substitution and addition reactions with hydrocarbons and carboxylic acids and their derivatives. There are organic chlorides in which the chlorine is present as a chloride ion , e.g. B. in the hydrochlorides and the N- acyliminium chlorides.
In the carboxylic acid chlorides , a chlorine atom is bound to an acyl radical via a strongly polarized covalent bond . In the chloroalkanes - traditional name: alkyl chlorides - the respective chlorine atom is bound to a carbon atom via a less polarized covalent bond. The designation of these non-salty organic compounds as "chloride" is questionable, but nonetheless common.
Usage and examples
Other important chlorides are:
- Lithium chloride - LiCl
- Potassium Chloride - KCl
- Cesium chloride - CsCl
- Magnesium chloride - MgCl 2
- Calcium chloride - CaCl 2
- Lead (II) chloride - PbCl 2
- Iron (II) chloride - FeCl 2
- Iron (III) chloride - FeCl 3
- Silver chloride - AgCl
- Zinc chloride - ZnCl 2
- Mercury (I) chloride - Hg 2 Cl 2
- Mercury (II) chloride - HgCl 2
- Ammonium chloride - NH 4 Cl
- Barium chloride - BaCl 2
- Aluminum chloride - AlCl 3
- Diborotetrachloride - B 2 Cl 4
Many chlorides of these salts form hydrates .
Examples of organic chlorides with a covalent carbon-chlorine bond:
- Methylene chloride (better term: dichloromethane) - CH 2 Cl 2
- Allyl chloride - CH 2 = CHCH 2 Cl
- Benzyl chloride - C 6 H 5 CH 2 Cl
- Other halides: fluorides , bromides , iodides
- Other salts of oxo acids containing chlorine: hypochlorites , chlorite , chlorates , perchlorates
- Electrophilic substitution , nucleophilic substitution , electrophilic addition , nucleophilic addition