Organic
Reaction
Mechanisms
Exam
EXAM 1.
Total Duration: 90 minutes
Instructions:
Answer all questions.
For multiple-choice questions, circle the correct answer.
Provide detailed explanations for short answer and problem-solving
questions.
Show all work for calculations and mechanisms.
Section A: Multiple-Choice Questions (20 Questions)
1. Which of the following best describes the transition state of an SN2
reaction?
, A) A carbocation intermediate.
B) A transition state with both the nucleophile and leaving group.
C) A planar intermediate.
D) An intermediate with a positively charged center.
2. In which of the following scenarios would an E2 mechanism be preferred
over an E1 mechanism?
A) Tertiary substrate with a weak base.
B) Secondary substrate with a strong base.
C) Primary substrate with a polar protic solvent.
D) Secondary substrate with a weak base.
3. Which of the following is true for SN1 reactions?
A) They proceed with inversion of configuration.
B) They are favored by strong nucleophiles.
C) They involve a carbocation intermediate.
D) They have a single concerted step.
4. What factor is least likely to affect the rate of an E1 reaction?
A) The concentration of the base.
B) The stability of the carbocation intermediate.
C) The leaving group ability.
D) The solvent polarity.
5. Which of the following substrates is most likely to undergo an SN2
reaction?
A) Tertiary alkyl halide.
B) Secondary alkyl halide.
C) Primary alkyl halide.
D) Allylic alkyl halide.
6. The rate of an E2 reaction depends on:
A) The concentration of the substrate only.
B) The concentration of both the substrate and base.
C) The concentration of the nucleophile only.
D) The temperature only.
7. Which type of solvent is best suited for an SN2 reaction?
A) Polar protic solvent.
B) Non-polar solvent.
C) Polar aprotic solvent.
D) Aprotic non-polar solvent.
8. In an SN1 reaction, the major product is typically:
A) Formed via a concerted mechanism.
B) A racemic mixture.
C) Formed with inversion of configuration.
, D) The result of a strong nucleophile attack.
9. Which of the following would favor an E1 reaction over an E2 reaction?
A) A strong base.
B) A tertiary substrate.
C) A polar aprotic solvent.
D) A secondary substrate.
10. What is the primary feature of the E2 mechanism?
A) Formation of a carbocation intermediate.
B) Simultaneous deprotonation and elimination.
C) Formation of a racemic mixture.
D) Single transition state with nucleophile attack.
11. In which of the following situations would an SN1 reaction be favored?
A) Primary alkyl halide with a strong nucleophile.
B) Secondary alkyl halide with a weak nucleophile.
C) Tertiary alkyl halide with a weak nucleophile.
D) Primary alkyl halide with a polar aprotic solvent.
12. What characteristic is common to both SN2 and E2 mechanisms?
A) Both involve a carbocation intermediate.
B) Both reactions are favored by strong bases.
C) Both have a single-step transition state.
D) Both require a polar protic solvent.
13. In an E1 reaction, the rate-determining step involves:
A) Protonation of the substrate.
B) Formation of a carbocation intermediate.
C) Nucleophilic attack.
D) Base abstraction of a proton.
14. Which of the following statements about SN2 reactions is true?
A) The nucleophile attacks from the opposite side of the leaving group.
B) The reaction proceeds via a carbocation intermediate.
C) The reaction rate is independent of the nucleophile concentration.
D) The reaction is favored by bulky substrates.
15. Which substrate would most likely undergo an E2 reaction?
A) Methyl bromide.
B) Secondary bromide with a strong base.
C) Primary bromide with a weak base.
D) Tertiary bromide with a non-polar solvent.
16. For an SN1 reaction, the major product is typically:
A) The result of an inversion of configuration.
B) The result of a racemization process.
C) The result of a concerted mechanism.
Reaction
Mechanisms
Exam
EXAM 1.
Total Duration: 90 minutes
Instructions:
Answer all questions.
For multiple-choice questions, circle the correct answer.
Provide detailed explanations for short answer and problem-solving
questions.
Show all work for calculations and mechanisms.
Section A: Multiple-Choice Questions (20 Questions)
1. Which of the following best describes the transition state of an SN2
reaction?
, A) A carbocation intermediate.
B) A transition state with both the nucleophile and leaving group.
C) A planar intermediate.
D) An intermediate with a positively charged center.
2. In which of the following scenarios would an E2 mechanism be preferred
over an E1 mechanism?
A) Tertiary substrate with a weak base.
B) Secondary substrate with a strong base.
C) Primary substrate with a polar protic solvent.
D) Secondary substrate with a weak base.
3. Which of the following is true for SN1 reactions?
A) They proceed with inversion of configuration.
B) They are favored by strong nucleophiles.
C) They involve a carbocation intermediate.
D) They have a single concerted step.
4. What factor is least likely to affect the rate of an E1 reaction?
A) The concentration of the base.
B) The stability of the carbocation intermediate.
C) The leaving group ability.
D) The solvent polarity.
5. Which of the following substrates is most likely to undergo an SN2
reaction?
A) Tertiary alkyl halide.
B) Secondary alkyl halide.
C) Primary alkyl halide.
D) Allylic alkyl halide.
6. The rate of an E2 reaction depends on:
A) The concentration of the substrate only.
B) The concentration of both the substrate and base.
C) The concentration of the nucleophile only.
D) The temperature only.
7. Which type of solvent is best suited for an SN2 reaction?
A) Polar protic solvent.
B) Non-polar solvent.
C) Polar aprotic solvent.
D) Aprotic non-polar solvent.
8. In an SN1 reaction, the major product is typically:
A) Formed via a concerted mechanism.
B) A racemic mixture.
C) Formed with inversion of configuration.
, D) The result of a strong nucleophile attack.
9. Which of the following would favor an E1 reaction over an E2 reaction?
A) A strong base.
B) A tertiary substrate.
C) A polar aprotic solvent.
D) A secondary substrate.
10. What is the primary feature of the E2 mechanism?
A) Formation of a carbocation intermediate.
B) Simultaneous deprotonation and elimination.
C) Formation of a racemic mixture.
D) Single transition state with nucleophile attack.
11. In which of the following situations would an SN1 reaction be favored?
A) Primary alkyl halide with a strong nucleophile.
B) Secondary alkyl halide with a weak nucleophile.
C) Tertiary alkyl halide with a weak nucleophile.
D) Primary alkyl halide with a polar aprotic solvent.
12. What characteristic is common to both SN2 and E2 mechanisms?
A) Both involve a carbocation intermediate.
B) Both reactions are favored by strong bases.
C) Both have a single-step transition state.
D) Both require a polar protic solvent.
13. In an E1 reaction, the rate-determining step involves:
A) Protonation of the substrate.
B) Formation of a carbocation intermediate.
C) Nucleophilic attack.
D) Base abstraction of a proton.
14. Which of the following statements about SN2 reactions is true?
A) The nucleophile attacks from the opposite side of the leaving group.
B) The reaction proceeds via a carbocation intermediate.
C) The reaction rate is independent of the nucleophile concentration.
D) The reaction is favored by bulky substrates.
15. Which substrate would most likely undergo an E2 reaction?
A) Methyl bromide.
B) Secondary bromide with a strong base.
C) Primary bromide with a weak base.
D) Tertiary bromide with a non-polar solvent.
16. For an SN1 reaction, the major product is typically:
A) The result of an inversion of configuration.
B) The result of a racemization process.
C) The result of a concerted mechanism.
