Deck 6: Organic Halogen Compounds

Question 1

Which of the following is an incorrect representation of relative nucleophile strength?

A) (^-NH₂ > F^-)
B) HO^- > HS^-
C) CH₃^- > HO^-
D) CH₃O^- > CH₃OH
E) I^- > Br^-

Answer 1

HO^- > HS^-

Question 2

Which of the following is the best nucleophile?

A) H₂O
B) HO^-
C) HS^-
D) H₃S
E) all are the same

Answer 2

HS^-

Question 3

The slowest step of an S_N1 reaction involves:

A) attack of the nucleophile on the substrate to form a pentavalent carbon.
B) breaking the bond between the carbon and the leaving group to give a carbocation.
C) combination of a nucleophile with the carbocation to give the product.
D) loss of a proton from the nucleophile to give the product.
E) none of the above.

Answer 3

breaking the bond between the carbon and the leaving group to give a carbocation.

Question 4

Which of the following is the best leaving group?

A) F^-
B) Cl^-
C) I^-
D) Br^-
E) H₂N^-

Question 5

Which of the following bromides will react faster with CH₃OH in an S_N1 reaction?

A)
B)
C)
D)
E)

Question 6

Which of the following is the best nucleophile?

A) H₂O
B) CH₄
C) NH₃
D) HF

Question 7

Which of the following is the strongest base?

A) H₂O
B) (^-OH)
C) NH₃
D) (^-NH₂)
E) F^-

Question 8

Which statement is true for S_N2 reactions?

A) The rate of the reaction is dependent on the stability of a carbocation.
B) The rate of reaction is dependent on just the substrate.
C) The fastest reaction will occur with a tertiary halide.
D) Displacement occurs with inversion of configuration.
E) The mechanism is a two step process.

Question 9

What is the mechanism of the following reaction?

A) S_N1
B) S_N2
C) E1
D) E2
E) both A and B

Question 10

CH₃CH₂C(CH₃)₂Br + (CH₃)₃CO^-K⁺ are most likely to react by

A) a free radical chain mechanism.
B) the S_N1 mechanism.
C) the S_N2 mechanism.
D) the E1 mechanism.
E) the E2 mechanism.

Question 11

The expected S_N2 reactivity order of the following is:

A) 2 > 1 > 3
B) 2 > 3 > 1
C) 1 > 2 > 3
D) 1 > 3 > 2
E) 3 > 1 > 2

Question 12

The S_N2 mechanism for nucleophilic substitution reactions

A) involves two steps and occurs with inversion of configuration.
B) involves one step and occurs with inversion of configuration.
C) involves two steps and occurs with racemization.
D) involves one step and occurs with retention of configuration.
E) involves one step and occurs with racemization.

Question 13

The S_N1 mechanism for nucleophilic substitution reactions

A) involves one step and occurs fastest with primary halides.
B) involves one step and occurs fastest with tertiary halides.
C) involves two steps and occurs fastest with tertiary halides.
D) involves two steps and occurs fastest with primary halides.
E) involves one step and occurs fastest with aromatic halides.

Question 14

What is the IUPAC name of the following alkyl halide?

A) trans-p-bromotoluene
B) trans-4-methylcyclohexyl bromide
C) trans-4-methyl-1-bromocyclohexane
D) trans-1-bromo-4-methylcyclohexane
E) trans-p-bromomethylcyclohexane

Question 15

When (R)-3-bromo-3-methylhexane is treated with H₂O, racemic is produced.By what mechanism does this reaction occur?

A) S_N1
B) S_N2
C) E1
D) E2
E) cannot be explained by one mechanism

Question 16

Which statement(s) is/are true of an E1 elimination?

A) it is a two-step process and has the same first step as a S_N1 mechanism
B) it involves the formation of the carbocation from elimination of a good leaving group
C) a common competing reaction is rearrangement of a less stable carbocation to a more stable carbocation
D) the loss of a proton by the carbocation is a fast step
E) all of the above

Question 17

Which of the following structures represents 2,4,4-trichloroheptane?

A) I
B) II
C) III
D) IV
E) V

Question 18

Which bromide reacts fastest in S_N2 reactions?

A) CH₃Br
B) (CH₃) ₂CHBr
C) (CH₃) ₃CBr
D) (CH₃) ₃CCH₂Br
E) CH₃CH₂Br

Question 19

Which of the following is a polar aprotic solvent?

A) H₂O
B) CH₃CN
C) CH₃OH
D) (CH₃) ₂S=O
E) both B and D

Question 20

What is the IUPAC name of the following alkyl halide?

A) 2-bromo-6-methylheptane
B) 6-methyl-2-bromoheptane
C) 2-methyl-6-bromoheptane
D) 2-bromo-2-methylheptane
E) 2-bromo-5-isopropylpentane

Question 21

The major product of the reaction below is: is

A)
B)
C)
D)
E)

Question 22

What is the final product of the following sequence of reactions?

A) I
B) II
C) III
D) IV
E) III and IV

Question 23

What is the major product of the following reaction?

A)
B)
C)
D)
E) none of these

Question 24

The structure below represents the transition state for the reaction of

A) methanol with 2-bromopropene.
B) methoxide with 2-bromopropane.
C) sodium bromide with isopropyl methyl ether.
D) methanol with 2-bromopropane.
E) methoxide with 1-bromopropane.

Question 25

The major product of the following reaction is:

A) I
B) II
C) III
D) I and II
E) there is no major product

Question 26

Polyhalogenated aliphatic compounds have not been used as:

A) food preservatives
B) fire retardants
C) degreasing agents
D) insecticides
E) refrigerants

Question 27

What is the major product of the following reaction?

A)
B)
C)
D)
E)

Question 28

Which Fischer projection represents the product of the following reaction?

A)
B)
C)
D)
E)

Question 29

When 1-bromobutane is reacted with the bulky base, potassium tert-butoxide, in tert-butyl alcohol, the major elimination product is:

A) 1-butene
B) cis-2-butene
C) trans-2-butene
D) butyl tert-butyl ether
E) butyl alcohol

Question 30

The monomer used to prepare Teflon is

A) CH₂=CH₂
B) CH₂=CHCl
C) CH₃CH=CH₂
D) CF₂=CF₂
E) CH₂Cl₂

Question 31

The products of the following reactions are:

A) I, III
B) I, II, III
C) III, V
D) II, IV, V
E) II, III

Question 32

How many different E2 products can form from the dehydrohalogenation of 2-bromopentane?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 33

What alkyne is produced when sodium acetylide reacts with CH₃CH₂CH₂I?

A) 2-pentyne
B) 1-pentyne
C) 2-pentene
D) 1-pentene
E) butyne

Question 34

Which of the following halocarbons is the raw material for the synthesis of Teflon?

A) I
B) II
C) III
D) IV
E) V