Which chemical process is used to convert sulfur dioxide to sulfuric acid?

The conversion of sulfur dioxide to sulfuric acid is accomplished through the Contact process. This industrial method involves several steps, beginning with the oxidation of sulfur dioxide (SO₂) to sulfur trioxide (SO₃) in the presence of a vanadium(V) oxide catalyst. This reaction occurs at high temperature and pressure.

Once sulfur trioxide is formed, it can then be reacted with water to produce sulfuric acid (H₂SO₄). However, instead of adding water directly to sulfur trioxide (which can produce a corrosive mist), the SO₃ is usually absorbed into existing sulfuric acid to form oleum, which is then mixed with water to make concentrated sulfuric acid.

The Contact process is highly efficient and is the most common method for producing sulfuric acid on an industrial scale. It utilizes the principles of equilibrium and optimization of conditions to maximize sulfuric acid yield. Understanding this process is vital as sulfuric acid is a key industrial chemical with numerous applications.

In contrast, the other processes mentioned do not relate to the conversion of sulfur dioxide to sulfuric acid: the Pargel reaction is not a recognized term in the context of chemical processes, the Haber process is specifically for synthesizing ammonia from nitrogen and hydrogen,