Question

Which of the following compounds undergoes electrophilic substitution most readily?

• A. Nitrobenzene
• B. Toluene
• C. Benzene
• D. Benzoic acid

Hint:

\textbf{Tip:} Electron-donating groups (e.g., –CH\(_3\)) activate benzene rings; electron-withdrawing groups (e.g., –NO\(_2\)) deactivate them.

Answer 1

The Correct Option is B

The compound that undergoes electrophilic substitution most readily among the given options is determined by the electron-donating or electron-withdrawing nature of the substituents on the aromatic ring. Electrophilic substitution reactions occur more readily in aromatic compounds that have electron-donating groups, which activate the ring by increasing electron density. Let's evaluate the options: 

• Nitrobenzene: Contains a nitro group (-NO₂) that is electron-withdrawing, deactivating the benzene ring towards electrophilic substitution.
• Toluene: Contains a methyl group (-CH₃), which is electron-donating. This increases the electron density on the benzene ring, activating it for electrophilic substitution reactions.
• Benzene: A standard aromatic compound with no substituents. It is less reactive than toluene due to the lack of electron-donating groups.
• Benzoic acid: Contains a carboxyl group (-COOH), which is electron-withdrawing, thus deactivating the benzene ring.

Among these, Toluene undergoes electrophilic substitution most readily, due to the electron-donating methyl group that enhances the reactivity of the aromatic ring towards electrophiles.