sulfur trioxide


noun Chemistry.

an irritant, corrosive, low-melting solid, SO3, obtained by the oxidation of sulfur dioxide, used as an intermediate in the manufacture of sulfuric acid.

Origin of sulfur trioxide

First recorded in 1865–70
Also called sulfuric anhydride.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Science definitions for sulfur trioxide

sulfur trioxide


A colorless, highly reactive, corrosive compound that exists either as a liquid or as a solid. As a solid, it exists in three forms that may coexist in a given sample. Sulfur trioxide is used as an intermediate in manufacturing sulfuric acid, and in making sulfonates from organic compounds. Chemical formula: SO3.
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