Organic Chemistry: Sn2 and Sn1
Reactions Exam 2026 Questions and
Answers Graded A+
What is a Sn2 reaction? - Correct answer-Substitution reaction. It is a nucleophilic
reaction (thats what the N stands for). and it is bimolecular (indicated by the 2).
The bimolecular aspect refers to the fact tat there are 2 things bumping into one
another during the rate determining step of the mechanism.
What are electrophiles? - Correct answer-Groups with positive or partially positive
charges
What are nucleophiles? - Correct answer-Species with either negative charges or
nonbonding pairs of electrons that are available to form a bond.
The nucleus is positive thus nucleophiles are attracted to the nucleus
Which anion is the best leaving group and which is the worst? i.e. which is the
least electronegative (most stable) and which is the most electronegative (least
stable)? - Correct answer-Iodide is the best leaving group while fluoride is the
worst.
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, What part of the substrate does the nucleophile attack in Sn2 reactions? - Correct
answer-The back, the side away from the leaving group.
What is steric hindrance? - Correct answer-Steric hindrance refers to when large
groups on one of the reacting molecules inhibits that molecule from bumping into
others to cause a chemical reaction.
What type of substrates react the most slowly with respect to steric hindrance? -
Correct answer-3º groups react the most slowly since they have more groups which
can cause inhibition in bumping
What happens to the configuration of the substrate in an Sn2 reaction? - Correct
answer-The substrate undergoes an "inversion of configuration where the stereo
center changes.
Ex: Changing from (R) to (S)
What are Sn1 reactions? - Correct answer-They are unimolecular nucleophilic
reactions. There is only one molecule during the rate determining step.
During Sn1 reactions, what happens to the geometry of the carbocation when the
leaving group exits the carbon in the first step? - Correct answer-The leaving group
causes the geometry to be trigonal planar
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Reactions Exam 2026 Questions and
Answers Graded A+
What is a Sn2 reaction? - Correct answer-Substitution reaction. It is a nucleophilic
reaction (thats what the N stands for). and it is bimolecular (indicated by the 2).
The bimolecular aspect refers to the fact tat there are 2 things bumping into one
another during the rate determining step of the mechanism.
What are electrophiles? - Correct answer-Groups with positive or partially positive
charges
What are nucleophiles? - Correct answer-Species with either negative charges or
nonbonding pairs of electrons that are available to form a bond.
The nucleus is positive thus nucleophiles are attracted to the nucleus
Which anion is the best leaving group and which is the worst? i.e. which is the
least electronegative (most stable) and which is the most electronegative (least
stable)? - Correct answer-Iodide is the best leaving group while fluoride is the
worst.
©COPYRIGHT 2026, ALL RIGHTS RESERVED 1
, What part of the substrate does the nucleophile attack in Sn2 reactions? - Correct
answer-The back, the side away from the leaving group.
What is steric hindrance? - Correct answer-Steric hindrance refers to when large
groups on one of the reacting molecules inhibits that molecule from bumping into
others to cause a chemical reaction.
What type of substrates react the most slowly with respect to steric hindrance? -
Correct answer-3º groups react the most slowly since they have more groups which
can cause inhibition in bumping
What happens to the configuration of the substrate in an Sn2 reaction? - Correct
answer-The substrate undergoes an "inversion of configuration where the stereo
center changes.
Ex: Changing from (R) to (S)
What are Sn1 reactions? - Correct answer-They are unimolecular nucleophilic
reactions. There is only one molecule during the rate determining step.
During Sn1 reactions, what happens to the geometry of the carbocation when the
leaving group exits the carbon in the first step? - Correct answer-The leaving group
causes the geometry to be trigonal planar
©COPYRIGHT 2026, ALL RIGHTS RESERVED 2
