In organic and inorganic chemistry, nucleophilic substitution is a fundamental class of reactions in which an electron nucleophile selectively bonds with or attacks the positive or partially positive charge of an atom or a group of atoms to replace a so-called leaving group; the positive or partially positive atom is referred to as an electrophile. The whole molecular entity of which the electrophile and the leaving group are part is usually called the substrate

1. Chapter 8

2. • 1. Identify the nucleophile in the following
reaction.
•
•
•
•
A.
B.
C.
D.
CH3Br
OH¯
H2 O
Br¯

3. • 2. Identify the leaving group in the following
reaction.
•
•
•
•
A.
B.
C.
D.
CH3CH2Br
HS¯
Br¯
CH3OH

4. • 3. Which of the following cannot act as a
nucleophile?
•
•
•
•
A.
B.
C.
D.
NH3
H2O
I¯
CH4

5. 4.
•
•
•
•
In the SN2 reaction, the "2" stands for
A.
B.
C.
D.
two reactants in the reaction.
two steps in the reaction.
two intermediates in the reaction.
bimolecular kinetics for the reaction.

6. 5.
Which of the following undergoes a
substitution reaction with sodium cyanide in DMSO
at the fastest rate?
•
•
•
•
•
A.
B.
C.
D.
CH3CH2F
CH3CH2Cl
CH3CH2Br
CH3CH2I

7. 6.
1-Chloro-4-fluorobutane is reacted with one
equivalent of sodium iodide in acetone. During the
reaction a precipitate forms. What is the
precipitate?
•
•
•
•
A.
B.
C.
D.
FCH2CH2CH2CH2I
ClCH2CH2CH2CH2I
NaCl
NaF

8. • 7. The rate law for the following reaction is
•
•
•
•
A.
B.
C.
D.
rate = k[CH3CH2CH2Cl].
rate = k[CH3CH2CH2Cl][NaCN].
rate = k[CH3CH2CH2Cl][NaCN]2.
rate = k[NaCN].

9. • 8. Which of the following reacts the fastest
by the SN2 mechanism?
•
•
•
•
•
A.
B.
C.
D.
CH3Br
CH3CH2Br
(CH3)2CHBr
(CH3)3CBr

10. • 9. Give the product(s) of the following reaction?
•
•
•
•
A.
B.
C.
D.
A
B
C
a mixture of A and B

11. • 10. Which halide ion reacts the fastest with
cyclopentyl p-toluenesulfonate in ethanol/water?
•
•
•
•
A.
B.
C.
D.
A
B
C
D

12. • 11. Which one of the following species forms the
strongest ion-dipole attraction with 18-crown-6?
•
•
•
•
A.
B.
C.
D.
FK+
Cr2O72Br2

13. • 12. Identify the major product(s) in the
reaction of (R)-2-bromopentane with sodium
cyanide in DMSO?
•
•
•
•
A.
B.
C.
D.
(R)-2-cyanopentane
(S)-2-cyanopentane
racemic mixture of 2-cyanopentane
trans-2-pentene

14. • 13. Which of the following reacts fastest with methanol by the SN1
mechanism?
•
•
•
•
A.
B.
C.
D.
A
B
C
D

15. • 14. A pentacoordinate carbon is a transient
species in the _____ mechanism.
•
•
•
•
A.
B.
C.
D.
S N1
SN2
E1
E2

16. • 15. What is the leaving group in the following
reaction?
•
•
•
•
A.
B.
C.
D.
OHH2O
CH3CH2+
C1-

17. • 16. Considering the SN1, SN2, E1, and E2
mechanisms, the energy diagram shown below
corresponds to
•
•
•
•
A.
B.
C.
D.
only the SN1 mechanism.
only the SN2 mechanism.
both the SN1 and E1 mechanisms.
both the SN2 and E2 mechanisms.

18. • 17. Which of the following is the rate law for
the SN1 mechanism of an alkyl halide with a
nucleophile?
•
•
•
•
A.
B.
C.
D.
rate = k[alkyl halide]
rate = k[nucleophile]
rate = k[alkyl halide][nucleophile]
rate = k[alkyl halide]2[nucleophile]

19. • 18. Which of the following bases works best to
maximize the E2 product in the reaction shown below?
•
•
•
•
•
A.
B.
C.
D.
KOCH2CH3
NaOCH2CH3
NaOC(CH3)3
NaOH

20. 19. Which of the following does not correctly describe
SN2 reactions of alkyl halides?
• A. Tertiary halides react faster than secondary
halides.
• B. Rate of reaction depends on the concentrations of
both the alkyl halide and the nucleophile.
• C. The mechanism consists of a single step with no
intermediates.
• D. The transition state species has a pentavalent
carbon atom.