Sulfuric Acid from Sulfur Trioxide and Water—A Surprisingly Complex Reaction

On paper very simple, but in reality far more complicated—this applies to the formation of sulfuric acid in the atmosphere, which leads to the environmental problem of acid rain. In this reaction sulfur trioxide is transformed into sulfur dioxide, which reacts with water dimers to give sulfuric acid. Ab initio calculations as well as spectroscopic and kinetic studies have yielded new information on the reaction mechanism.