Iodides

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Silver iodide precipitate in the test tube
Copper (I) iodide, a preparation that can be synthesized from copper (II) sulphate solution and sodium iodide (insoluble in water)

The compounds of the chemical element iodine with metals are referred to as iodides (formerly: iodides ) (examples: silver iodide , copper (I) iodide ). These are the inorganic salts of hydroiodic acid (HI). Non-metal iodine compounds such as. B. denotes the covalent organic carbon-iodine compounds. Thus, there are also inorganic covalent iodides, such as. B. Boron triiodide .

The salt-like iodides contain in their ion lattice as negative lattice building blocks ( anions ) iodide ions (I - ), which are simply negatively charged. Important iodides are potassium iodide (KI) or sodium iodide (NaI).

Examples of organic iodides are iodomethane and iodoform . Another example are tetramethylammonium iodide and the group of substances called acyl iodides. Aromatic iodides (e.g. iodobenzene ) decompose photochemically into iodine radicals and aryl radicals, which are capable of many different reactions.

proof

Iodides in solution, heated with concentrated sulfuric acid , give violet vapors of elemental iodine .

They can also be detected wet-chemically with the classic detection reactions for halides . With chlorinated water as a detection agent, iodine is produced ( violet in hexane ). With silver nitrate solution , silver iodide precipitates as a whitish yellow precipitate.

Inorganic iodides

See also

Individual evidence

  1. ^ Gert Blumenthal, Dietmar Linke, Siegfried Vieth: Chemistry: Basic knowledge for engineers . Springer-Verlag, 2007, ISBN 978-3-8351-9047-4 ( google.de [accessed on September 22, 2019]).
  2. ^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, p. 605.
  3. ^ Hans Beyer and Wolfgang Walter : Organic Chemistry , S. Hirzel Verlag, Stuttgart, 1984, p. 134, ISBN 3-7776-0406-2 .
  4. ↑ Otto-Albrecht Neumüller (Ed.): Römpps Chemie-Lexikon. Volume 3: H-L. 8th revised and expanded edition. Franckh'sche Verlagshandlung, Stuttgart 1983, ISBN 3-440-04513-7 , p. 1913.

Web links

Wikibooks: Practical course in inorganic chemistry / iodide  - learning and teaching materials