Disulfurous acid

Disulfurous acid

Names
IUPAC name disulfurous acid
Other names pyrosulfurous acid
Identifiers
3D model (Jmol)	Interactive image
ChEBI	CHEBI:29252 Y
ChemSpider	26062 Y
PubChem CID	28020
InChI InChI=1S/H2O5S2/c1-6(2)7(3,4)5/h(H,1,2)(H,3,4,5) Y Key: WBZKQQHYRPRKNJ-UHFFFAOYSA-N Y 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).
Y  (what is YN ?)
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. 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.