Selenous acid

chemical compound

Selenous acid, also known as selenious acid, is a chemical compound. Its chemical formula is H2SeO3. It is an acid. It contains hydrogen and selenite ions.

Selenous acid[1]
Names
IUPAC names
Selenous acid
Selenic(IV) acid
Other names
Selenious acid
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.029.067
KEGG
UNII
  • O[Se+]([O-])O
Properties
H2SeO3
Molar mass 128.97 g/mol
Appearance white hygroscopic crystals
Density 3.0 g/cm3
Melting point decomposes at 70°C
very soluble
Solubility soluble in ethanol
Acidity (pKa) 2.46, 7.3[2]
Conjugate base Hydrogenselenite
−45.4·10−6 cm3/mol
Related compounds
Other anions selenic acid
hydrogen selenide
Other cations sodium selenite
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Properties change

Selenous acid is a weak acid. It can be heated to make selenium dioxide. It is more stable than sulfurous acid. It can be crystallized as a white solid. It is a weak oxidizing agent. It reacts with bases to make selenites.

Preparation change

It is made by dissolving selenium dioxide in water.

Uses change

It is used to dye steel a blue-grey color. It is used in the making of organic compounds.

Safety change

Selenous acid is very toxic. Just ingesting a small amount can kill you.

Related pages change

Sources change

  1. Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, Florida: CRC Press. pp. 4–81. ISBN 0-8493-0594-2.
  2. Ka and pKa for Polyprotic Acids. ucdsb.on.ca