# Production of sulfuric acid using sulfur dioxide

Is it possible to create sulfuric acid using sulfur dioxide directly dissolved in water? Usually, people oxidize the $\ce{SO2}$ to sulfur trioxide ($\ce{SO3}$) first. If this is possible, why is it not done industrially?

If you try to dissolve sulfur dioxide into water, you'll get sulfurous acid instead of sulfuric acid: $$\ce{H2O + SO2 <=> H+ + HSO3-}$$

There's a very good reading material on the Contact Process to help explain why we have opted for the specific industrial conditions.

• Sulfurous acid does not exist. It is an aqueous solution of sulfur dioxide. – Nilay Ghosh Jun 10 '16 at 16:05