Sulfurous acid

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An unstable acid formed when sulfur dioxide dissolves in water. Sulfurous acid is a strong oxidizing agent and is used to bleach straw and textiles. It is also used in paper pulp manufacturing. Other applications include disinfectant and preservative for fruits, nuts, wine, and other food.

Other Properties

Soluble in water.

pH of 0.1N solution=1.5

Composition H2SO3 (theoretical)
CAS 7782-99-2
Density 1.03
Molecular Weight mol. wt. = 82.07

Hazards and Safety

Toxic by ingestion and inhalation. Corrosive to skin. Causes severe burns.

Fisher Scientific: MSDS

Sources Checked for Data in Record

  • Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
  • Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
  • CRC Handbook of Chemistry and Physics, Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980 Comment: pH of 0.1N solution=1.5