Aromatic Compounds and Electrophilic Substitution - Case Studies
Q. In the nitration of toluene, what is the major product formed?
A.Ortho-nitrotoluene
B.Para-nitrotoluene
C.Meta-nitrotoluene
D.Toluene
Solution
The major product is para-nitrotoluene due to steric hindrance at the ortho position, making the para position more favorable for substitution.
Correct Answer: B — Para-nitrotoluene
Q. What is the expected product when anisole undergoes bromination?
A.Bromobenzene
B.Ortho-bromoanisole
C.Para-bromoanisole
D.No reaction
Solution
The expected product is para-bromoanisole, as the methoxy group is an electron-donating group that directs electrophilic substitution to the para position.
Correct Answer: C — Para-bromoanisole
Q. What is the IUPAC name of the compound formed when phenol is treated with acetic anhydride?
A.Acetophenone
B.Phenyl acetate
C.Benzyl acetate
D.Phenyl acetic acid
Solution
The compound formed is acetophenone, which results from the acetylation of phenol.
Correct Answer: A — Acetophenone
Q. What is the product of the Friedel-Crafts alkylation of benzene with 1-bromopropane in the presence of AlCl3?
A.Propylbenzene
B.Isopropylbenzene
C.Benzyl bromide
D.Benzene
Solution
The product is propylbenzene, formed when benzene reacts with 1-bromopropane in the presence of AlCl3, which generates a propyl cation.
Correct Answer: A — Propylbenzene
Q. What is the role of sulfuric acid in the nitration of benzene?
A.Electrophile
B.Nucleophile
C.Catalyst
D.Solvent
Solution
Sulfuric acid acts as a catalyst in the nitration of benzene, facilitating the generation of the nitronium ion (NO2+) from nitric acid.
Correct Answer: C — Catalyst
Q. Which of the following compounds is an example of a phenolic compound?
A.Benzene
B.Phenol
C.Toluene
D.Aniline
Solution
Phenol is a classic example of a phenolic compound, characterized by a hydroxyl group (-OH) attached to a benzene ring.
Correct Answer: B — Phenol
Q. Which of the following compounds undergoes electrophilic substitution more readily?
A.Toluene
B.Benzene
C.Chlorobenzene
D.Nitrobenzene
Solution
Toluene undergoes electrophilic substitution more readily than benzene due to the electron-donating effect of the methyl group, which stabilizes the carbocation intermediate.
Correct Answer: A — Toluene
Q. Which substituent on a benzene ring is a strong deactivator and meta-director?
A.Methyl
B.Nitro
C.Hydroxyl
D.Ethyl
Solution
The nitro group is a strong deactivator and directs incoming electrophiles to the meta position due to its electron-withdrawing nature.
