Hypoiodous acid

Hypoiodous acid
  Hydrogen, H
  Oxygen, O
  Iodine, I
Names
IUPAC name
Hypoiodous acid
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
UNII
  • InChI=1S/HIO/c1-2/h2H checkY
    Key: GEOVEUCEIQCBKH-UHFFFAOYSA-N checkY
  • IO
Properties
HOI
Molar mass 143.911 g·mol−1
Acidity (pKa) 10.5 (in water, estimate)[1]
Conjugate base Hypoiodite
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Hypoiodous acid is an inorganic compound with the chemical formula HOI. It forms when an aqueous solution of iodine is treated with mercuric or silver salts. It rapidly decomposes by disproportionation:[2]

5 HIO → HIO3 + 2 I2 + 2 H2O

Hypoiodites of alkali and alkaline earth metals can be made in cold dilute solutions if iodine is added to their respective hydroxides. Hypoiodous acid is a weak acid with a pKa of about 11. The conjugate base is hypoiodite (IO−). Salts of this anion can be prepared by treating I2 with alkali hydroxides. They rapidly disproportionate to form iodides and iodates.[2]

  1. ^ Perrin, D. D., ed. (1982) [1969]. Ionisation Constants of Inorganic Acids and Bases in Aqueous Solution. IUPAC Chemical Data (2nd ed.). Oxford: Pergamon (published 1984). Entry 119. ISBN 0-08-029214-3. LCCN 82-16524.
  2. ^ a b Holleman, A.F. (2001). Wiberg, Nils (ed.). Inorganic chemistry (1st English ed.). San Diego, Calif. : Berlin: Academic Press, W. de Gruyter. ISBN 0-12-352651-5.