Short answers, pulled from the story.
Sulfuric acid is a mineral acid composed of sulfur, oxygen, and hydrogen, with the molecular formula H2SO4. It is a colorless, odorless, viscous liquid that is miscible with water and is also known historically as oil of vitriol.
Peregrine Phillips, a British vinegar merchant, patented the contact process in 1831. It is far more economical than earlier methods and today produces nearly all of the world's sulfuric acid.
As of the late twentieth century, roughly 60% of all sulfuric acid produced was used to manufacture fertilizers, particularly superphosphates, ammonium phosphate, and ammonium sulfates. It is also essential in petroleum refining, battery production, steel pickling, and chemical synthesis.
World production in 2004 was about 180 million tonnes. By 2022, global production was estimated at 260 million tonnes.
Adding water to concentrated sulfuric acid creates a thin layer of water on top of the denser acid. The intense heat generated in that layer can boil the water and disperse a sulfuric acid aerosol, or cause an explosion. The correct procedure is always to add acid to water, never the reverse.
On Earth, dilute sulfuric acid forms as acid rain when atmospheric sulfur dioxide is oxidized in the presence of water, and it also forms in acid mine drainage from oxidizing sulfide minerals. In the stratosphere, volcanic sulfur dioxide produces sulfuric acid aerosols that form the stratospheric aerosol layer. The clouds of Venus are made of concentrated sulfuric acid, and sulfuric acid ice has been detected on Jupiter's moon Europa.