Sulfur dioxide solution
SIGALD/247626 - ACS reagent, ≥6%
Synonym: Sulfurous acid; Sulfurous anhydride
CAS Number: 7782-99-2
Empirical Formula (Hill Notation): H2O3S
Molecular Weight: 82.08
EC Number: 231-973-1
MDL Number: MFCD00011335
Linear Formula: H2SO3
Product Type: Chemical
anion traces | chloride (Cl-): ≤5 ppm |
assay | ≥6% SO2 basis (by Na2S2O3, titration) |
cation traces | Fe: ≤5 ppm |
heavy metals (as Pb): ≤2 ppm | |
concentration | ≥6% |
density | 1.03 g/mL at 25 °C (lit.) |
form | liquid |
grade | ACS reagent |
ign. residue | ≤0.005% |
InChI | 1S/H2O3S/c1-4(2)3/h(H2,1, |
InChI key | LSNNMFCWUKXFEE-UHFFFAOYSA |
Quality Level | 200 ![]() |
SMILES string | OS(O)=O |
vapor density | 2.3 (vs air) |
Application: | Sulfurous acid can be used as a reducing agent in chemical synthesis. |
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. |
Packaging: | 100, 500 g in glass bottle |
Packaging: | 2 kg in glass bottle |
Symbol | ![]() ![]() |
Signal word | Danger |
Hazard statements | H314 - H332 |
Precautionary statements | P261 - P271 - P280 - P303 + P361 + P353 - P304 + P340 + P310 - P305 + P351 + P338 |
Hazard Codes | C |
Risk Statements | 20-34 |
Safety Statements | 26-36/37/39-45 |
RIDADR | UN 1833 8 / PGII |
WGK Germany | WGK 1 |
Flash Point(F) | Not applicable |
Flash Point(C) | Not applicable |
Purity | ≥6% SO2 basis (by Na2S2O3, titration) |
Density | 1.03 g/mL at 25 °C (lit.) |
UNSPSC | 12352300 |