Organic Mechanisms: SN1, SN2, E1, E2
Characteristics and Reactions Exam 2026
Questions and Answers Graded A+
What are the characteristics of an E2 mechanism? - Correct answer-It is
bimolecular, one-step, requires a strong base, and involves anti-periplanar
geometry.
What are the characteristics of an E1 mechanism? - Correct answer-It is
unimolecular, two-step (involving a carbocation intermediate), requires a weak
base, and often uses protic solvents.
What are the characteristics of an SN2 mechanism? - Correct answer-It is
bimolecular, one-step, requires a strong nucleophile, involves backside attack, and
results in inversion of configuration.
What are the characteristics of an SN1 mechanism? - Correct answer-It is
unimolecular, two-step (involving a carbocation intermediate), requires a weak
nucleophile, and results in racemization.
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, Is a good leaving group required for SN2, SN1, E2, and E1 mechanisms? - Correct
answer-Yes, all four mechanisms require a good leaving group to proceed.
Which mechanisms are sensitive to steric hindrance? - Correct answer-SN2 is
highly sensitive to sterics; E2 is also affected, particularly by the size of the base.
What is the preferred substrate for SN2 reactions? - Correct answer-Methyl,
primary, and secondary substrates are preferred; tertiary substrates are generally
too sterically hindered.
What is the preferred substrate for SN1 and E1 reactions? - Correct answer-
Tertiary and allylic substrates are preferred due to the stability of the carbocation
intermediate.
What type of solvent is preferred for SN2 reactions? - Correct answer-Polar aprotic
solvents are preferred to avoid solvating the nucleophile and reducing its reactivity.
What type of solvent is preferred for SN1 and E1 reactions? - Correct answer-Polar
protic solvents are preferred to stabilize the carbocation intermediate and the
leaving group.
What is the stereochemical outcome of an SN2 reaction? - Correct answer-
Inversion of configuration at the electrophilic center.
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Characteristics and Reactions Exam 2026
Questions and Answers Graded A+
What are the characteristics of an E2 mechanism? - Correct answer-It is
bimolecular, one-step, requires a strong base, and involves anti-periplanar
geometry.
What are the characteristics of an E1 mechanism? - Correct answer-It is
unimolecular, two-step (involving a carbocation intermediate), requires a weak
base, and often uses protic solvents.
What are the characteristics of an SN2 mechanism? - Correct answer-It is
bimolecular, one-step, requires a strong nucleophile, involves backside attack, and
results in inversion of configuration.
What are the characteristics of an SN1 mechanism? - Correct answer-It is
unimolecular, two-step (involving a carbocation intermediate), requires a weak
nucleophile, and results in racemization.
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, Is a good leaving group required for SN2, SN1, E2, and E1 mechanisms? - Correct
answer-Yes, all four mechanisms require a good leaving group to proceed.
Which mechanisms are sensitive to steric hindrance? - Correct answer-SN2 is
highly sensitive to sterics; E2 is also affected, particularly by the size of the base.
What is the preferred substrate for SN2 reactions? - Correct answer-Methyl,
primary, and secondary substrates are preferred; tertiary substrates are generally
too sterically hindered.
What is the preferred substrate for SN1 and E1 reactions? - Correct answer-
Tertiary and allylic substrates are preferred due to the stability of the carbocation
intermediate.
What type of solvent is preferred for SN2 reactions? - Correct answer-Polar aprotic
solvents are preferred to avoid solvating the nucleophile and reducing its reactivity.
What type of solvent is preferred for SN1 and E1 reactions? - Correct answer-Polar
protic solvents are preferred to stabilize the carbocation intermediate and the
leaving group.
What is the stereochemical outcome of an SN2 reaction? - Correct answer-
Inversion of configuration at the electrophilic center.
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