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247626

Sigma-Aldrich

Sulfur dioxide solution

ACS reagent, ≥6%

Synonym(s):

Sulfurous acid, Sulfurous anhydride

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About This Item

Linear Formula:
H2SO3
CAS Number:
7782-99-2
Molecular Weight:
82.08
EC Number:
231-973-1
MDL number:
MFCD00011335
UNSPSC Code:
12352300
PubChem Substance ID:
329752746
NACRES:
NB.24

grade

ACS reagent

Quality Level

200

vapor density

2.3 (vs air)

assay

≥6% SO2 basis (by Na2S2O3, titration)

form

liquid

concentration

≥6%

ign. residue

≤0.005%

density

1.03 g/mL at 25 °C (lit.)

anion traces

chloride (Cl-): ≤5 ppm

cation traces

Fe: ≤5 ppm
heavy metals (as Pb): ≤2 ppm

SMILES string

OS(O)=O

InChI

1S/H2O3S/c1-4(2)3/h(H2,1,2,3)

InChI key

LSNNMFCWUKXFEE-UHFFFAOYSA-N

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General description

Sulfurous acid (H2SO3), a weak diprotic acid, is formed when sulfur dioxide (SO2) dissolves in water. Sulfurous acid is a complex mixture of various hydrates of SO2 and the ions H3O+, S2O52- and HSO3-. The predominant species present in the solution are pH dependent.

Application

Sulfurous acid can be used as a reducing agent in chemical synthesis.

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Product No.
Description
Pricing

pictograms

CorrosionExclamation mark
GHS05,GHS07

signalword

Danger

hcodes

H314,H332

Hazard Classifications

Acute Tox. 4 Inhalation - Eye Dam. 1 - Skin Corr. 1B

wgk_germany

WGK 1

flash_point_f

Not applicable

flash_point_c

Not applicable

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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