Title: Sulfur Dioxide
CAS Registry Number: 7446-09-5
Additional Names: Sulfurous anhydride; sulfurous oxide
Molecular Formula: O2S
Molecular Weight: 64.06
Percent Composition: O 49.95%, S 50.05%
Line Formula: SO2
Literature References: Liquid SO2 used as solvent: Waddington, Non-aqueous Solvent Systems, T. C. Waddington, Ed. (Academic Press, New York, 1965) pp 253-284. Review of toxicology and human exposure: Toxicological Profile for Sulfur Dioxide (PB99-122020, 1998) 223 pp. Brief review of synthetic applications: F. Fonquerne, Synlett 2005, 1340-1341.
Properties: Colorless, nonflammable gas; strong suffocating odor. Condenses at -10° and ordinary pressure to a colorless liquid. d (liq) 1.5. mp -72°. bp -10°. Mixed with oxygen and passed over red-hot Pt, it is converted into SO3. With water forms sulfurous acid (H2SO3). Bleaches vegetable colors. Soly: in water 17.7% at 0°, 11.9% at 15°, 8.5% at 25°, 6.4% at 35°; in alcohol 25%; in methanol 32%; also sol in chloroform or ether.
Melting point: mp -72°
Boiling point: bp -10°
Density: d (liq) 1.5
CAUTION: Potential symptoms of overexposure are irritation of eyes, nose and throat, rhinorrhea; choking, coughing; reflex bronchoconstriction; direct contact with liquid may cause frostbite. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 288.
Use: Preserving fruits, vegetables, etc.; disinfectant in breweries and food factories; bleaching textile fibers, straw, wicker ware, gelatin, glue, beet sugars. Solvent and reagent in organic synthesis. |