"sulfur trioxide." YourDictionary, n.d. Web. 16 January 2019. <https://www.yourdictionary.com/sulfur-trioxide>.
sulfur trioxide. (n.d.). Retrieved January 16th, 2019, from https://www.yourdictionary.com/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.