Magnesium sulfite

Magnesium sulfite
Names
	IUPAC name Magnesium sulfite
	Other names Magnesium sulphite
Identifiers
CAS Number	7757-88-2 ;
ChemSpider	2282946;
ECHA InfoCard	100.028.932
EC Number	231-825-6;
PubChem CID	3014583;
UNII	792J6K230W ;
CompTox Dashboard (EPA)	DTXSID50884418 ;
Properties
Chemical formula	MgSO; 3 (anhydrous); MgSO; 3·6H; 2O
Molar mass	104.368200 g/mol (anhydrous) ; 212.4599 g/mol (hexahydrate)
Solubility in water	5.2g/L at 298.2K (hexahydrate)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Magnesium sulfite is the magnesium salt of sulfurous acid with the formula MgSO
₃. Its most common hydrated form has 6 water molecules making it a hexahydrate, MgSO
₃·6H
₂O. When heated above 40 °C (104 °F), it is dehydrated to magnesium sulfite trihydrate, or MgSO
₃·3H
₂O.^[1] The anhydrous form is hygroscopic, meaning that it readily absorbs water from the air.

Solubility tables of MgSO3 hydrates PDF: ^[2]

References

^ Nývlt, J., "Solubilities of Magnesium Sulfite," Journal of Thermal Analysis and Calorimetry, Volume 66, Number 2 / November, 2001
^ [1], H.D.Lutz, Dept. of Chemistry, University of Slegen.