Which one is known as the oil of vitriol? A. H2SO3 B. H2SO4 C. H2S2O7 D. H2S2O5

H2SO3
H2SO4
H2S2O7
H2S2O5

The correct answer is $\boxed{\text{B}}$, sulfuric acid. Sulfuric acid is a mineral acid with the molecular formula $\ce{H2SO4}$. It is a colorless, odorless, and viscous liquid that is highly corrosive. Sulfuric acid is one of the most important industrial chemicals and is used in a wide variety of applications, including the production of fertilizers, detergents, and explosives.

The other options are incorrect. $\text{A}$, sulfurous acid, is a colorless, odorless, and deliquescent gas that is less corrosive than sulfuric acid. $\text{C}$, disulfuric acid, is also known as oleum and is a fuming liquid that is even more corrosive than sulfuric acid. $\text{D}$, thiosulfuric acid, is a colorless, odorless, and water-soluble liquid that is less corrosive than sulfuric acid.

Sulfuric acid was first produced by the alchemist Jabir ibn Hayyan in the 8th century. It was originally called “oil of vitriol” because it was obtained by distilling vitriol, which is a naturally occurring sulfate mineral. Sulfuric acid was not widely used until the 18th century, when it was used to produce sulfuric nitrate, which was used in gunpowder. Sulfuric acid is now one of the most important industrial chemicals and is used in a wide variety of applications.