Sulfur trioxide is a chemical compound with the formula SO3. It is a colorless liquid at room temperature and has a strong, pungent odor. This compound is highly reactive and can form sulfuric acid when it comes into contact with water. Due to its reactivity, sulfur trioxide is primarily used in the production of sulfuric acid, which is an important industrial chemical. In addition to its role in producing sulfuric acid, sulfur trioxide is also used in the manufacture of detergents and in the synthesis of various chemicals. It is produced through the oxidation of sulfur dioxide in the presence of a catalyst. Proper handling and storage are essential, as sulfur trioxide can cause severe burns and is hazardous to health.