Disulfurous acid

Disulfurous acid

Names
IUPAC name disulfurous acid [1]
Other names pyrosulfurous acid
Identifiers
ChEBI	CHEBI:29252
ChemSpider	26062
Jmol interactive 3D	Image
PubChem	28020
InChI InChI=1S/H2O5S2/c1-6(2)7(3,4)5/h(H,1,2)(H,3,4,5) Key: WBZKQQHYRPRKNJ-UHFFFAOYSA-N InChI=1S/H2O5S2/c1-6(2)7(3,4)5/h(H,1,2)(H,3,4,5)
SMILES O=S(=O)(O)S(=O)O
Properties
Chemical formula	H2S2O5
Molar mass	146.14 g mol^−1
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

Disulfurous acid or pyrosulfurous acid is an oxoacid of sulfur with the formula H₂S₂O₅. The salts of disulfurous acid are called disulfites or metabisulfites. Disulfurous acid is, like sulfurous acid (H₂SO₃), a phantom acid, which does not exist in the free state. ^[2] In contrast to disulfate (S₂O₇⁻), disulfite has two directly connected sulfur atoms. The oxidation state of the sulfur atom bonded to 3 oxygen atoms is +5 while oxidation number of other sulfur atom is +3.

References

1. International Union of Pure and Applied Chemistry (2005). Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005). Cambridge (UK): RSC–IUPAC. ISBN 0-85404-438-8. p. 130. Electronic version.
2. Holleman, Wiberg: Inorganic chemistry Academic Press @ Google Books. 2001; pp. 537-540.