Calcium sulfite

Calcium sulfite

Names
IUPAC name Calcium sulfite
Other names Sulfurous acid, calcium salt (1:1) E226
Identifiers
CAS Number	10257-55-3 Y
3D model (JSmol)	Interactive image
ChemSpider	8329549 Y
ECHA InfoCard	100.030.529
E number	E226 (preservatives)
PubChem CID	159274
CompTox Dashboard (EPA)	DTXSID10883104
InChI InChI=1S/Ca.H2O3S/c;1-4(2)3/h;(H2,1,2,3)/q+2;/p-2 Y Key: GBAOBIBJACZTNA-UHFFFAOYSA-L Y InChI=1/Ca.H2O3S/c;1-4(2)3/h;(H2,1,2,3)/q+2;/p-2 Key: GBAOBIBJACZTNA-NUQVWONBAU
SMILES [Ca+2].[O-]S([O-])=O
Properties
Chemical formula	CaSO3
Molar mass	120.17 g/mol
Melting point	600 °C (1,112 °F; 873 K)
Solubility in water	0.0043 g/100 mL, 18C
Hazards
Flash point	Non-flammable
Related compounds
Other anions	Calcium sulfate
Other cations	Sodium sulfite
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Calcium sulfite, or calcium sulphite, is a chemical compound which is the calcium salt of sulfurous acid with the molecular formula CaSO₃. As a food additive it is used as a preservative under the E number E226. It is commonly used in preserving wine, cider, fruit juice, canned fruit and vegetables.

Like other metal sulfites, calcium sulfite reacts with acids to produce a calcium salt, sulfur dioxide gas and water. For this reason, CaSO₃ is not a desirable compound in drywall - when humid (with the natural acidity of carbon dioxide found in the air), it releases sulfur dioxide and carbon dioxide is absorbed to form calcium carbonate.