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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
Pricing and availability is not currently available.

grade

ACS reagent

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

Signal Word

Danger

Hazard Statements

H314,H332

Hazard Classifications

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

Storage Class Code

8B - Non-combustible corrosive hazardous materials

WGK

WGK 1

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

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Certificates of Analysis (COA)

Lot/Batch Number
MKCT8760
MKCQ0685
MKCK6803
SHBJ4747
SHBH2057V

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The thermodynamic ionization constants of sulfurous acid at 25?1.
Tartar HV and Garretson HH.
Journal of the American Chemical Society, 63(3), 808-816 (1941)
M Kharina et al.
Applied biochemistry and biotechnology, 179(2), 307-320 (2016-01-29)
Sulfurous acid was used for pretreatment of sugar beet pulp (SBP) in order to achieve high efficiency of both extraction of carbohydrates and subsequent enzymatic hydrolysis of the remaining solids. The main advantage of sulfurous acid usage as pretreatment agent
Miquel Pascual et al.
Journal of the science of food and agriculture, 95(15), 3067-3076 (2015-07-16)
Rainfed viticulture, mainly in semi-arid environments, is limited by environmental variability, particularly precipitation and its seasonal distribution, and soil water availability, thus ultimately determining the final quality of grape and wine. Studies on the feasibility of practices such as canopy
Daniela Vullo et al.
Bioorganic & medicinal chemistry letters, 16(12), 3139-3143 (2006-04-20)
An inhibition study of the cytosolic carbonic anhydrase (CA, EC 4.2.1.1) isozyme VII (hCA VII) with anions has been conducted. Cyanate, cyanide, and hydrogensulfite were weak hCA VII inhibitors (K(I)s in the range of 7.3-15.2 mM). Cl- and HCO3- showed
Heng Yu et al.
Bioresource technology, 199, 188-193 (2015-09-06)
This study established a new more neutral magnesium bisulfate pretreatment (MBSP) using magnesium bisulfate as sulfonating agent for improving the enzymatic hydrolysis efficiency of corn stover. Using the MBSP with 5.21% magnesium bisulfate, 170°C and pH 5.2 for 60 min
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Questions

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  1. How can I determine the shelf life / expiration / retest date of this product?

    1 answer

    1. If this product has an expiration or retest date, it will be shown on the Certificate of Analysis (COA, CofA). If there is no retest or expiration date listed on the product's COA, we do not have suitable stability data to determine a shelf life. For these products, the only date on the COA will be the release date; a retest, expiration, or use-by-date will not be displayed.
      For all products, we recommend handling per defined conditions as printed in our product literature and website product descriptions. We recommend that products should be routinely inspected by customers to ensure they perform as expected.
      For products without retest or expiration dates, our standard warranty of 1 year from the date of shipment is applicable.
      For more information, please refer to the Product Dating Information document: https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/marketing/global/documents/449/386/product-dating-information-mk.pdf

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  2. How is shipping temperature determined? And how is it related to the product storage temperature?

    1 answer

    1. Products may be shipped at a different temperature than the recommended long-term storage temperature. If the product quality is sensitive to short-term exposure to conditions other than the recommended long-term storage, it will be shipped on wet or dry-ice. If the product quality is NOT affected by short-term exposure to conditions other than the recommended long-term storage, it will be shipped at ambient temperature. As shipping routes are configured for minimum transit times, shipping at ambient temperature helps control shipping costs for our customers. For more information, please refer to the Storage and Transport Conditions document: https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/marketing/global/documents/316/622/storage-transport-conditions-mk.pdf

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