Electrophilic Substitution Reaction MCQs

By: Prof. Dr. Fazal Rehman | Last updated: May 22, 2025

1. : What does the Aromatic bromination catalyzed by the Lewis acid thalium acetate give?
(A) Meta isomer
(B) Ortho isomer
(C) Para isomer
(D) Para and ortho isomer

2. : What does an activating substituent group activate?
(A) Ortho position
(B) Meta position
(C) Both ortho and para positions
(D) Para position

3. : Which of the following has the highest activation of the benzene ring?
(A) –NH₂
(B) –OH
(C) –NHCOCH₃
(D) –C₆H₅

4. : What acts as catalyst in the nitration of benzene?
(A) Conc. H₂SO₄
(B) Dil. HCl
(C) Conc. HCl
(D) Dil. H₂SO₄

5. : What is the rate determining step in electrophilic substitution reaction?
(A) Generation of electrophile
(B) All of the mentioned
(C) Formation of product
(D) Attack by an electrophilic reagent on benzene ring

6. : What is the necessary condition for desulphonation?
(A) High concentration of sulphonating agent
(B) Low concentration of water
(C) Remove volatile hydrocarbon by steam distillation
(D) A large excess of fuming sulphuric acid

7. : What does a deactivating substituent group direct?
(A) Meta position
(B) Para position
(C) Both ortho and para positions
(D) Ortho position

8. : In Cannizzaro reaction, two molecules of aldehydes react to produce which of the following?
(A) Alcohol only
(B) Carboxylic acid only
(C) Alcohol, carboxylic acid and ketone
(D) Alcohol and carboxylic acid

9. : What acts as electrophile in halogenation?
(A) Halonium ion
(B) Sulphonium ion
(C) Nitronium ion
(D) Acylium ion

10. : HBr reacts fastest with which of the following?
(A) Propan-2-ol
(B) Propan-1-ol
(C) 2-methylpropan-2-ol
(D) 2-methylpropan-1-ol

11. : Which of the following is not a product of the reaction of benzene with CH₃Cl and AlCl₃?
(A) Toluene
(B) p-Xylene
(C) o-Xylene
(D) Isopropyl benzene

12. : What is the product of Friedel-Crafts Acylation reactions?
(A) Arylketone
(B) Alkylamine
(C) Alkylbenzene
(D) Halobenzene

13. : What is the reaction in which benzene reacts with alkyl halide in the presence of a Lewis acid to produce alkylbenzene?
(A) Nitration
(B) Friedel-Crafts Alkylation
(C) Friedel-Crafts Acylation
(D) Halogenation

14. : Which of the following is a meta-directing group?
(A) –NHCOCH₃
(B) –OCH₃
(C) –OH
(D) –COOH

15. : Which of the following is the most stable carbonium ion?
(A) Methyl carbonium ion
(B) 3° (tertiary) carbonium ion
(C) 1° (primary) carbonium ion
(D) 2° (secondary) carbonium ion

16. : What is the method to convert benzene into n-propyl benzene?
(A) Friedel-Crafts Alkylation
(B) Friedel-Crafts Acylation followed by Clemmensen reduction
(C) Friedel-Crafts Alkylation followed by Clemmensen reduction
(D) Friedel-Crafts Acylation

17. : Which of the following is an ortho-para directing group?
(A) –CN
(B) –NO₂
(C) –NHCOCH₃
(D) –CHO

18. : Fuming sulphuric acid is a solution of how much % SO₃ in conc. H₂SO₄?
(A) 7
(B) 9
(C) 8
(D) 10

19. : Which of the following compounds can be most readily sulphonated?
(A) Toluene
(B) Nitrobenzene
(C) Benzene
(D) Chlorobenzene