Engineering Chemistry Questions and Answers – Nucleophillic Substitution Reaction

This set of Engineering Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Nucleophilic Substitution Reaction”.

1. The atom which defines the structure of a family of organic compounds and their properties is called ___________
a) Resonating structure
b) Homologous structure
c) Functional group
d) Nucleophile
View Answer

2. The functional group in alkyl halide is ___________
a) Hydroxyl group
b) Halogen atom
c) Inert gas
d) All of the mentioned
View Answer

3. The halide ion is an extremely ___________
a) Weak base
b) Weak acid
c) Strong base
d) Strong acid
View Answer

4. When the nucleophile :OR attacks the RX, the resultant product will be ___________
a) R – OH
b) ROR
c) R:CN
d) RNHR
View Answer

5. Select the correct statement from the following option.
a) S_N2 reaction follows second order kinetics
b) No intermediate is involved in S_N2 mechanism
c) S_N2 reactions are one-step reaction
d) All of the mentioned
View Answer

6. The reactivity order of alkyl halides in S_N2 is ___________
a) CH₃ X > 1⁰ > 2⁰ > 3⁰
b) CH₃ X > 2⁰ > 1⁰ > 3⁰
c) CH₃ X > 3⁰ > 1⁰ > 2⁰
d) CH₃ X > 3⁰ > 2⁰ > 1⁰
View Answer

7. S_N1 reaction involves heterolysis to form the carbocation as an intermediate.
a) True
b) False
View Answer

8. Which step in S_N1 reaction is a slow rate determining step?
a) Attack of nucleophile
b) Formation of a racemic mixture
c) Formation of a transition state
d) All of the mentioned
View Answer

9. A low concentration of nucleophile favours the ___________
a) S_N2 reaction
b) S_N1 reaction
c) Both S_N1 and S_N1 reaction
d) None of the mentioned
View Answer

10. Which of the following reactions are favoured by polar aprotic solvent?
a) S_N1 reactions
b) S_N2 reactions
c) Both S_N1 and S_N1 reactions
d) None of the mentioned
View Answer

11. Arrange the following in the decreasing order of leaving group in nucleophilic substitution reaction.
a) H^– > Cl^– > HO^– > Br^– > CH₃COO^–
b) Cl^– > Br^– > HO^– > H^– > CH₃COO^–
c) Cl^– > Br^– > CH₃COO ^– > HO^– > H^–
d) HO^– > CH₃COO ^– > H^– > Br^– > Cl^–
View Answer

12. Reaction of alcohol with SOCl₂ is ___________
a) S_N1
b) S_N2
c) S_NAr
d) S_Ni
View Answer

13. The nucleophilic substitutions do not occur in haloarenes because ___________
a) The carbon-halogen bond is much shorter
b) The carbon-halogen bond is stronger compared to that in haloalkanes
c) The lone pair of electrons on the halogen participates in delocalisation with the π-electrons of benzene ring
d) All of the mentioned
View Answer

14. Which of the following drastic condition is required for the substitution in haloarenes?
a) High temperature
b) High pressure
c) Strong concentrated reagent
d) All of the mentioned
View Answer

15. The rate of nucleophilic substitution reactions are higher in the presence of ___________
a) Electron withdrawing groups
b) Electron releasing groups
c) Both electron withdrawing and releasing groups
d) None of the mentioned
View Answer

Sanfoundry Global Education & Learning Series – Engineering Chemistry.

To practice all areas of Engineering Chemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.