Sodium metabisulfite

Sodium metabisulfite
Names
	Other names Sodium pyrosulfite; Sodium disulfite;
Identifiers
CAS Number	7681-57-4 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:114786 ;
ChEMBL	ChEMBL2016976 ;
ECHA InfoCard	100.028.794
EC Number	231-673-0;
E number	E223 (preservatives)
PubChem CID	656671;
RTECS number	UX8225000;
UNII	4VON5FNS3C ;
CompTox Dashboard (EPA)	DTXSID0029684 ;
	InChI InChI=1S/2Na.H2O5S2/c;;1-6(2)7(3,4)5/h;;(H,1,2)(H,3,4,5)/q2*+1;/p-2;
	SMILES [O-]S(=O)S(=O)(=O)[O-].[Na+].[Na+];
Properties
Chemical formula	Na2S2O5
Molar mass	190.107 g/mol
Appearance	White to yellow powder
Odor	Faint SO2
Density	1.48 g/cm3
Melting point	170 °C (338 °F; 443 K) decomposition begins at 150 °C
Solubility in water	45.1 g/100 mL (0 °C); 65.3 g/100 mL (20 °C); 81.7 g 100 mL (100 °C);
Solubility	Very soluble in glycerol ; Slightly soluble in ethanol
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H318
Precautionary statements	P264, P270, P280, P301+P312, P305+P351+P338, P310, P330, P501
NFPA 704 (fire diamond)	2 0 1
	NIOSH (US health exposure limits):
PEL (Permissible)	None
REL (Recommended)	TWA 5 mg/m3
IDLH (Immediate danger)	N.D.
Safety data sheet (SDS)	Mallinckrodt MSDS
Related compounds
Other anions	Sodium sulfite; Sodium bisulfite
Other cations	Potassium metabisulfite
Related compounds	Sodium dithionite; Sodium thiosulfate; Sodium sulfate
	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

Sodium metabisulfite or sodium pyrosulfite (IUPAC spelling; Br. E. sodium metabisulphite or sodium pyrosulphite) is an inorganic compound of chemical formula Na₂S₂O₅. The substance is sometimes referred to as disodium metabisulfite. It is used as a disinfectant, antioxidant, and preservative agent. When dissolved in water it forms sodium bisulfite.

Names


Other names Sodium pyrosulfite Sodium disulfite
Identifiers
CAS Number	7681-57-4^Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:114786^N
ChEMBL	ChEMBL2016976^N
ECHA InfoCard	100.028.794
EC Number	231-673-0
E number	E223 (preservatives)
PubChem CID	656671
RTECS number	UX8225000
UNII	4VON5FNS3C^Y
CompTox Dashboard (EPA)	DTXSID0029684
InChI InChI=1S/2Na.H2O5S2/c;;1-6(2)7(3,4)5/h;;(H,1,2)(H,3,4,5)/q2*+1;/p-2
SMILES [O-]S(=O)S(=O)(=O)[O-].[Na+].[Na+]
Properties
Chemical formula	Na₂S₂O₅
Molar mass	190.107 g/mol
Appearance	White to yellow powder
Odor	Faint SO₂
Density	1.48 g/cm³
Melting point	170 °C (338 °F; 443 K) decomposition begins at 150 °C
Solubility in water	45.1 g/100 mL (0 °C) 65.3 g/100 mL (20 °C) 81.7 g 100 mL (100 °C)
Solubility	Very soluble in glycerol Slightly soluble in ethanol
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H318
Precautionary statements	P264, P270, P280, P301+P312, P305+P351+P338, P310, P330, P501
NFPA 704 (fire diamond)	2 0 1
NIOSH (US health exposure limits):
PEL (Permissible)	None
REL (Recommended)	TWA 5 mg/m³
IDLH (Immediate danger)	N.D.
Safety data sheet (SDS)	Mallinckrodt MSDS
Related compounds
Other anions	Sodium sulfite Sodium bisulfite
Other cations	Potassium metabisulfite
Related compounds	Sodium dithionite Sodium thiosulfate Sodium sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is ^YN ?) Infobox references