For 10 points, name this diprotic acid has chemical formula H2SO4.
This compound is introduced to nitroparrafins in an early step of the Nef reaction. In an early method of producing this compound, oxides of nitrogen were used in the conversion of a certain dioxide into a corresponding trioxide. A more modern method involves burning pyrite in the excess air, and the second step of that process uses a vanadium oxide catalyst. A compound called oleum is reacted with water to produce this compound.  The former process was done in a chamber lined with lead, and the latter process is the contact process. For 10 points, name this diprotic acid has chemical formula H2SO4.
This compound is introduced to nitroparrafins in an early step of the Nef reaction.
{sulfuric} acid [accept {H2SO4} until mentioned; accept {oil} of {vitriol} at any point]