The mechanism for the electrophilic aromatic substitution reaction of toluene with nitric acid to form nitrobenzene involves the following steps:1. Formation of the electrophile: Nitric acid HNO3 reacts with a strong acid catalyst, typically sulfuric acid H2SO4 , to form the nitronium ion NO2+ , which acts as the electrophile in this reaction.HNO3 + H2SO4 NO2+ + HSO4- + H2O2. Electrophilic attack: The nitronium ion NO2+ attacks the toluene molecule at the carbon atom of the benzene ring, forming a resonance-stabilized carbocation intermediate. The presence of the electron-donating methyl group on the benzene ring increases the electron density, making the ring more nucleophilic and susceptible to electrophilic attack.3. Deprotonation: A base, usually the bisulfate ion HSO4- formed in the first step, abstracts a proton from the carbocation intermediate, restoring the aromaticity of the benzene ring and forming nitrobenzene as the final product.The presence of a methyl group on the benzene ring affects the rate and regiochemistry of the reaction in the following ways:1. Rate: The methyl group is an electron-donating group, which increases the electron density on the benzene ring. This makes the ring more nucleophilic and reactive towards electrophiles, such as the nitronium ion, thus increasing the rate of the reaction.2. Regiochemistry: The methyl group directs the electrophilic substitution to the ortho and para positions of the benzene ring due to its electron-donating nature. This is because the methyl group stabilizes the carbocation intermediate formed during the reaction through resonance, making the ortho and para positions more favorable for electrophilic attack. In the case of toluene, the para position is often the major product due to less steric hindrance compared to the ortho position.