Methylbenzene reacts with a mixture of concentrated nitric acid and concentrated sulfuric acid - AQA - A-Level Chemistry - Question 20 - 2019 - Paper 3

The reaction of methylbenzene with a mixture of concentrated nitric acid and concentrated sulfuric acid involves the electrophilic substitution mechanism. This is because the nitric acid acts as an electrophile, and it is substituted into the methylbenzene ring, replacing a hydrogen atom. In electrophilic substitution, the aromatic system retains its structure and stability, as one of the hydrogen atoms is replaced by the incoming electrophile.