sulfur trioxide

noun

, Chemistry.

1. an irritant, corrosive, low-melting solid, SO 3 , obtained by the oxidation of sulfur dioxide, used as an intermediate in the manufacture of sulfuric acid.

sulfur trioxide

1. 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: SO 3 .

Word History and Origins

Origin of sulfur trioxide¹

First recorded in 1865–70