For 10 points, name this acid produced by adding water to sulfur trioxide.
This compound used to be manufactured with the use of a nitrogen dioxide catalyst, though a vanadium oxide catalyst is now more common. It can be used as a desiccant, as its reaction with water is highly exothermic and may release enough energy to boil the water. The lead-chamber process has been replaced by the contact process as the most common method for producing this compound, the most synthesized industrial chemical in the United States. For 10 points, name this acid produced by adding water to sulfur trioxide.
This compound used to be manufactured with the use of a nitrogen dioxide catalyst, though a vanadium oxide catalyst is now more common.
{sulfuric} acid [or {H2SO4}]