The Contact Process is an industrial method used to produce sulfuric acid, one of the most important chemicals in the world. This process involves the oxidation of sulfur dioxide (SO2) to sulfur trioxide (SO3) using a catalyst, typically vanadium(V) oxide. The reaction occurs in a series of reactors at high temperatures and pressures to maximize efficiency. After producing SO3, it is then absorbed in sulfuric acid to form oleum, which can be further diluted with water to produce concentrated sulfuric acid. The Contact Process is favored for its high yield and relatively low energy requirements compared to older methods.