Aromatic Compounds and Electrophilic Substitution - Problem Set
Q. In the nitration of benzene, which reagent is used to generate the nitronium ion (NO2+)?
A.HNO3
B.H2SO4
C.HCl
D.NaNO2
Solution
Concentrated sulfuric acid (H2SO4) is used to generate the nitronium ion (NO2+) from nitric acid (HNO3) in the nitration of benzene.
Correct Answer: B — H2SO4
Q. What is the product of the Friedel-Crafts acylation of benzene with acetyl chloride (CH3COCl)?
A.Acetophenone
B.Benzophenone
C.Benzyl acetate
D.Phenyl acetate
Solution
The product is acetophenone, formed when benzene reacts with acetyl chloride in the presence of a Lewis acid catalyst.
Correct Answer: A — Acetophenone
Q. What is the stereochemistry of the product formed from the electrophilic substitution of 1,2-dimethylbenzene (o-xylene)?
A.R
B.S
C.R and S
D.None
Solution
The product can have both R and S configurations due to the presence of two methyl groups that can influence the orientation of the incoming electrophile.
Correct Answer: C — R and S
Q. Which of the following compounds will undergo electrophilic substitution more readily?
A.Benzene
B.Toluene
C.Chlorobenzene
D.Nitrobenzene
Solution
Toluene will undergo electrophilic substitution more readily than benzene due to the electron-donating effect of the methyl group.
Correct Answer: B — Toluene
Q. Which of the following is a common electrophile used in electrophilic aromatic substitution reactions?
A.Bromine
B.Benzene
C.Alkane
D.Alkene
Solution
Bromine is a common electrophile used in electrophilic aromatic substitution, often activated by a Lewis acid.
Correct Answer: A — Bromine
Q. Which substituent on a benzene ring is considered an electron-donating group?
A.Nitro group
B.Hydroxyl group
C.Carboxylic acid
D.Halogen
Solution
The hydroxyl group (-OH) is an electron-donating group, which activates the benzene ring towards electrophilic substitution.
