Nomenclature
CAS number: 7446-09-5
Sulfurous anhydride; sulfurous oxide.
O
2S; mol wt 64.06.
O 49.95%, S 50.05%.
SO
2.
Description and 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. Poisonous; corrosive. 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.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.