Question 1

Which of the following is NOT a necessary condition for an $$E2$$ elimination reaction to occur efficiently?

Accepted Answer

The nucleophile is weak.

Question 2

During the radical chlorination of 2,4-dimethylpentane, which position is most likely to yield the major monochlorinated product?

Accepted Answer

The tertiary carbon at position 4.

Question 3

Which of the following statements about $$S_N2$$ reactions is TRUE?

Accepted Answer

Steric hindrance at the electrophilic carbon decreases the reaction rate.

Question 4

Which of the following reagents would best convert a primary alcohol to a primary alkyl bromide?

Accepted Answer

$$\mathrm{$$PBr_3$$}$$

Question 5

Consider the following reaction: $$\mathrm{CH_3CH_2Br}$$ + $$\mathrm{NaOH}$$ $$\rightarrow$$ $$\mathrm{CH_3CH_2OH}$$ + $$\mathrm{NaBr}. $$What is the mechanism?

Accepted Answer

$$S_N2$$

Question 6

Which of the following best explains why $$S_N1$$ reactions are faster in polar protic solvents?

Accepted Answer

Polar protic solvents stabilize the carbocation intermediate.

Question 7

Which of the following compounds would react fastest in an $$S_N2$$ reaction?

Accepted Answer

1-bromobutane

Question 8

A student attempts to synthesize tert-butyl ether from tert-butyl alcohol and ethanol. Which method would be most effective?

Accepted Answer

React tert-butyl bromide with sodium ethoxide.

Question 9

Which of the following is the best method to prepare 1-bromopropane from 1-propanol?

Accepted Answer

Treat 1-propanol with $$\mathrm{$$PBr_3$$}.$$

Question 10

Which of the following statements about the $$E1$$ mechanism is FALSE?

Accepted Answer

The reaction is concerted.

Question 11

Which of the following is the major product when 2-bromobutane is treated with sodium ethoxide in ethanol?

Accepted Answer

2-butene

Question 12

Which of the following best describes the stereochemistry of $$S_N2$$ reactions?

Accepted Answer

Inversion of configuration

Question 13

Which of the following conditions would favor an $$S_N1$$ reaction over an $$S_N2$$ reaction?

Accepted Answer

A tertiary alkyl halide in a polar protic solvent

Question 14

Which of the following is the best nucleophile for an $$S_N2$$ reaction in DMSO?

Accepted Answer

$$\mathrm{CH_3O^-}$$

Question 15

Which of the following statements about the reactivity of alkyl halides in $$S_N2$$ reactions is correct?

Accepted Answer

Methyl halides react faster than primary halides.

Question 16

Which of the following is the best method to synthesize 2-butanol from 2-bromobutane?

Accepted Answer

React 2-bromobutane with aqueous $$\mathrm{NaOH}.$$

Question 17

Which of the following is the major product when 2-methyl-2-butanol is treated with concentrated $$\mathrm{H_2SO_4}$$?

Accepted Answer

2-methyl-2-butene

Question 18

Which of the following statements about the $$E2$$ mechanism is TRUE?

Accepted Answer

The reaction requires anti-coplanar geometry of the leaving group and hydrogen.

Question 19

Which of the following is the best method to prepare tert-butyl chloride from tert-butyl alcohol?

Accepted Answer

React tert-butyl alcohol with $$\mathrm{HCl}.$$

Question 20

Which of the following is the major product when 1-bromopentane is treated with sodium ethoxide in ethanol?

Accepted Answer

1-pentene

Organic Chemistry II: Reaction Mechanisms, Substitution and Elimination, and Synthesis

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