Answer to Question #90957 in Organic Chemistry for sagaram

Question

What is the role of sulphuric acid in the mixed acid?

Answer 1

For example, sulfuric acid activates of nitric acid in the nitration of benzene. The first step in the nitration of benzene is to activate HNO₃ with sulfuric acid to produce a stronger electrophile, the nitronium ion. The source of the nitronium ion is through the protonation of nitric acid by sulfuric acid, which causes the loss of a water molecule and formation of a nitronium  ion.

References:

1. Chemistry: LibreTexts [Electronic resource]. – Mode of access: https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Supplemental_Modules_(Organic_Chemistry)/Arenes/Reactivity_of_Arenes/Nitration_and_Sulfonation_of_Benzene. – Date of access: 19.06.2019.