Amphoteric

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As amphoter (from ancient Greek ἀμφοτέρως , amphotéros "of both kinds") one describes different material properties in chemistry and physics .

chemistry

The simplest amino acid ( glycine , left) forms z. B. a salt with both caustic soda and hydrochloric acid .

In chemistry , a substance is called amphoteric, which - depending on the environment or reactant - reacts in one way or another.

  • Acid-base amphoters are also known as ampholytes . These can react both as acids and as bases . Amphoteric substances react to stronger bases such as acids and to stronger acids such as bases. The amphoterics include various metal oxides and metal hydroxides (see table) and the amino acids .
  • As redox-amphoteric refers to materials which both can have a reducing oxidizing too. Example: hydrogen peroxide
  • Amphoteric surfactants have a cationic and an anionic part and are important as surface-active substances.

Amphoteric hydroxides are those hydroxide compounds that are soluble in both acidic and alkaline media:

hydroxide dissolved in acid dissolved in the basic
Copper (II) hydroxide : Cu (OH) 2 Cu 2+ [Cu (OH) 4 ] 2−
Tin hydroxide : Sn (OH) 2/4 Sn 2 + / 4 + [Sn (OH) 4/6 ] 2-
Antimony hydroxide : Sb (OH) 3/5 Sb 3 + / 5 + [Sb (OH) 4/6 ] -
Aluminum hydroxide : Al (OH) 3 Al 3+ [Al (OH) 4 ] -
Chromium (III) hydroxide : Cr (OH) 3 Cr 3+ [Cr (OH) 6 ] 3−
Lead hydroxide : Pb (OH) 2 Pb 2+ [Pb (OH) 3 ] -
Zinc hydroxide : Zn (OH) 2 Zn 2+ [Zn (OH) 4 ] 2−
Beryllium hydroxide : Be (OH) 2 Be 2+ [Be (OH) 4 ] 2−

physics

In solid-state physics , those dopants are designated as amphoteric when doping , which can act both as acceptor and donor .

Web links

Wiktionary: Amphoter  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ a b Brockhaus ABC chemistry. Volume 1: A - K. VEB FA Brockhaus Verlag, Leipzig 1965, p. 80.
  2. ↑ Otto-Albrecht Neumüller (Ed.): Römpps Chemie-Lexikon. Volume 1: A-Cl. 8th revised and expanded edition. Franckh'sche Verlagshandlung, Stuttgart 1979, ISBN 3-440-04511-0 , p. 196.