247626

Sulfur dioxide solution

ACS reagent, ≥6%

• Synonym(s): Sulfurous acid, Sulfurous anhydride
• 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

Properties

• 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

Description

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⁺, S₂O₅^2- and HSO^3-. The predominant species present in the solution are pH dependent.

Application

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

Safety Information

• Pictograms: GHS05,GHS07
• Signal Word: Danger
• Hazard Statements: H314 - H332
• Precautionary Statements: P261 - P271 - P280 - P303 + P361 + P353 - P304 + P340 + P310 - P305 + P351 + P338
• 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