Potassium metabisulfite

Potassium metabisulfite
Names
	Other names Potassium pyrosulfite; Dipotassium disulfite; Potassium metabisulphite; Dipotassium disulphite;
Identifiers
CAS Number	16731-55-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	26061 ;
ECHA InfoCard	100.037.072
E number	E224 (preservatives)
PubChem CID	28019;
RTECS number	TT4920000;
UNII	65OE787Q7W ;
CompTox Dashboard (EPA)	DTXSID1021293 ;
	InChI InChI=1S/2K.H2O5S2/c;;1-6(2)7(3,4)5/h;;(H,1,2)(H,3,4,5)/q2+1;/p-2 Key: RWPGFSMJFRPDDP-UHFFFAOYSA-L ; InChI=1/2K.H2O5S2/c;;1-6(2)7(3,4)5/h;;(H,1,2)(H,3,4,5)/q2+1;/p-2 Key: RWPGFSMJFRPDDP-NUQVWONBAF;
	SMILES [K+].[K+].[O-]S(=O)S([O-])(=O)=O;
Properties
Chemical formula	K2O5S2
Molar mass	222.31 g·mol−1
Appearance	White crystalline powder
Odor	Pungent (sulfur dioxide)
Density	2.34 g/cm3 (solid)
Melting point	190 °C (374 °F; 463 K) decomposes
Solubility in water	450 g/L (20 °C)
Solubility	Insoluble in ethanol
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Irritant, asthma risk
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H315, H318, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P310, P312, P321, P332+P313, P362, P403+P233, P405, P501
NFPA 704 (fire diamond)	1 0 0
Safety data sheet (SDS)	ICSC 1175
Related compounds
Other anions	Potassium bisulfite; Potassium sulfite
Other cations	Sodium metabisulfite
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Potassium metabisulfite, K₂S₂O₅, also known as potassium pyrosulfite, is a white crystalline powder with a pungent odour. It is mainly used as an antioxidant or chemical sterilant. As a disulfite, it is chemically very similar to sodium metabisulfite, with which it is sometimes used interchangeably. Potassium metabisulfite has a monoclinic crystal structure.

Names



Other names Potassium pyrosulfite Dipotassium disulfite Potassium metabisulphite Dipotassium disulphite
Identifiers
CAS Number	16731-55-8^Y
3D model (JSmol)	Interactive image
ChemSpider	26061^Y
ECHA InfoCard	100.037.072
E number	E224 (preservatives)
PubChem CID	28019
RTECS number	TT4920000
UNII	65OE787Q7W^Y
CompTox Dashboard (EPA)	DTXSID1021293
InChI InChI=1S/2K.H2O5S2/c;;1-6(2)7(3,4)5/h;;(H,1,2)(H,3,4,5)/q2+1;/p-2^Y Key: RWPGFSMJFRPDDP-UHFFFAOYSA-L^Y InChI=1/2K.H2O5S2/c;;1-6(2)7(3,4)5/h;;(H,1,2)(H,3,4,5)/q2+1;/p-2 Key: RWPGFSMJFRPDDP-NUQVWONBAF
SMILES [K+].[K+].[O-]S(=O)S([O-])(=O)=O
Properties
Chemical formula	K₂O₅S₂
Molar mass	222.31 g·mol⁻¹
Appearance	White crystalline powder
Odor	Pungent (sulfur dioxide)
Density	2.34 g/cm³ (solid)
Melting point	190 °C (374 °F; 463 K) decomposes
Solubility in water	450 g/L (20 °C)
Solubility	Insoluble in ethanol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Irritant, asthma risk
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H315, H318, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P310, P312, P321, P332+P313, P362, P403+P233, P405, P501
NFPA 704 (fire diamond)	1 0 0
Safety data sheet (SDS)	ICSC 1175
Related compounds
Other anions	Potassium bisulfite Potassium sulfite
Other cations	Sodium metabisulfite
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