$$\text{Rate} = k[\text{alkyl halide}]$$

$$\text{methyl} \u003e 1^\circ \u003e 2^\circ \u003e 3^\circ$$

Question 1

Which of the following statements best explains why tertiary alkyl halides do not undergo SN2 reactions?

Accepted Answer

Steric hindrance around the electrophilic carbon prevents the nucleophile from attacking the back side.

Question 2

Which of the following solvents would most likely increase the rate of an SN2 reaction involving sodium iodide and 1-bromopropane?

Accepted Answer

Dimethyl sulfoxide (DMSO)

Question 3

Which of the following is the correct IUPAC name for the compound shown below?

CH3CH2CH(Br)CH2CH3

Accepted Answer

3-bromopentane

Question 4

Which of the following best describes the rate law for an SN1 reaction?

Accepted Answer

$$	ext{Rate} = k[	ext{alkyl halide}]$$

Question 5

Which of the following is a geminal dihalide?

Accepted Answer

CHBr2CH3

Question 6

Which of the following statements about the SN2 reaction mechanism is correct?

Accepted Answer

It involves a concerted, one-step mechanism.

Question 7

Which of the following is the best leaving group for a nucleophilic substitution reaction?

Accepted Answer

$$	ext{I}^-$$

Question 8

A reaction of 2-bromopropane with water yields a racemic mixture of 2-propanol. Which mechanism is most likely?

Accepted Answer

SN1

Question 9

Which of the following factors increases the rate of an SN1 reaction?

Accepted Answer

A more stable carbocation intermediate

Question 10

Which of the following is the correct order of reactivity for alkyl halides in SN2 reactions?

Accepted Answer

$$	ext{methyl} \u003e 1^\circ \u003e 2^\circ \u003e 3^\circ$$

Question 11

Which of the following best explains why bromination is more selective than chlorination in the free radical halogenation of alkanes?

Accepted Answer

Bromine radicals are less reactive and more selective for the most stable radical intermediate.

Question 12

Which of the following is a vicinal dihalide?

Accepted Answer

CH2BrCH2Cl

Question 13

Which of the following statements about the stereochemistry of SN2 reactions is correct?

Accepted Answer

SN2 reactions result in inversion of configuration (Walden inversion).

Question 14

Which of the following is the best description of a polar protic solvent?

Accepted Answer

A solvent that contains acidic hydrogens and can hydrogen bond.

Question 15

Which of the following is a real-world consequence of the use of Freons (chlorofluorocarbons) as refrigerants?

Accepted Answer

They contribute to the depletion of the ozone layer.

Question 16

Which of the following statements about carbocation rearrangements in SN1 reactions is correct?

Accepted Answer

Hydride or methyl shifts can occur to form a more stable carbocation.

Question 17

Which of the following is the correct trend in nucleophilicity for halide ions in polar protic solvents?

Accepted Answer

$$	ext{I}^- \u003e 	ext{Br}^- \u003e 	ext{Cl}^- \u003e 	ext{F}^-$$

Question 18

Which of the following is a common use of alkyl halides in industry?

Accepted Answer

As solvents and refrigerants

Question 19

Which of the following best explains why SN1 reactions often lead to racemization at a chiral center?

Accepted Answer

The nucleophile attacks from both sides of the planar carbocation intermediate.

Alkyl Halides and Nucleophilic Substitution: Structure, Properties, and Mechanisms

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