Selenite (group of substances)

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Selenites are the salts of the selenious acid H 2 SeO 3 . The salts contain the selenite ion (SeO 3 2− ) as an anion .

Selenous acid is a biprotonic acid. Hence, among the salts, there exist

  • Selenites (M I 2 SeO 3 ), which are also called normal, neutral selenites or diselenites and
  • Hydrogen selenites (M I HSeO 3 ), which are also known as acid selenites .

The acid strength of selenious acid ( pK s values of 2.62 and 8.32) is weaker than that of the sulfur dioxide .

Occurrence

Some Selenite are as natural formations in the form of minerals known as, among others, the hydrous Nickelselenit Ahlfeldit , the hydrous Kupferselenit Chalkomenit , the copper-iron-arsenic selenite Chaméanit , the hydrous uranyl -Selenit Haynesit that iron selenite Mandarinoit and the hydrous copper uranyl -Selenit marthozite .

use

Selenous acid is used in organic chemistry because of its oxidizing properties. For example, it oxidizes hydrogen sulfide to sulfur or hydrazine to nitrogen.

Individual evidence

  1. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 91st – 100th, improved and greatly expanded edition. Walter de Gruyter, Berlin 1985, ISBN 3-11-007511-3 , p. 530.