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

Question 1

Which of the following best describes a vinyl halide?

Accepted Answer

A halogen bonded to an sp$$^2$$ carbon of an alkene.

Question 2

Which of the following statements about the polarity of the carbon-halogen bond in alkyl halides is correct?

Accepted Answer

The carbon-halogen bond is polar, with carbon bearing a partial positive charge.

Question 3

What is the correct IUPAC name for the following compound: $$\mathrm{CH_3CH_2CH_2CH_2Br}$$?

Accepted Answer

1-bromobutane

Question 4

Which of the following is a geminal dihalide?

Accepted Answer

A compound with two halogens on the same carbon.

Question 5

Which of the following alkyl halides would have the highest boiling point?

Accepted Answer

CH$$_3CH$_2CH$_2Br$$

Question 6

Which of the following statements about the density of alkyl halides is correct?

Accepted Answer

Alkyl fluorides and alkyl chlorides with one chlorine are less dense than water.

Question 7

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

Accepted Answer

Bromine is less reactive and prefers to abstract hydrogens from more substituted carbons.

Question 8

Which of the following solvents would increase the rate of an $$S_N2$$ reaction?

Accepted Answer

Dimethyl sulfoxide (DMSO)

Question 9

What is the stereochemical outcome of an $$S_N2$$ reaction at a chiral center?

Accepted Answer

Inversion of configuration (Walden inversion)

Question 10

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

Accepted Answer

$$\mathrm{I^-}$$

Question 11

Which of the following alkyl halides will react fastest in an $$S_N1$$ reaction?

Accepted Answer

2-bromo-2-methylpropane

Question 12

Which of the following statements about the $$S_N1$$ reaction is correct?

Accepted Answer

The reaction proceeds via a carbocation intermediate.

Question 13

Which of the following is NOT a nucleophile?

Accepted Answer

$$\mathrm{CH_3CH_2OH}$$

Question 14

Which of the following best explains why $$I^- is a $$better nucleophile than $$F^- in $$protic solvents?

Accepted Answer

$$I^- is $$less basic and more polarizable, so it is less solvated and more reactive.

Question 15

Which of the following statements about the effect of substrate structure on $$S_N2$$ reactions is correct?

Accepted Answer

Primary alkyl halides react faster than secondary alkyl halides via $$S_N2.$$

Question 16

Which of the following is the correct rate law for an $$S_N2$$ reaction?

Accepted Answer

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

Question 17

A student attempts to synthesize an ether by reacting 1-bromopropane with sodium ethoxide in ethanol. Which mechanism is most likely?

Accepted Answer

$$S_N2$$

Question 18

Which of the following best describes the stereochemistry of the product when (S)-2-bromobutane undergoes $$S_N2$$ reaction with $$OH^-$$?

Accepted Answer

The product is (R)-2-butanol.

Question 19

Which of the following is most likely to undergo rearrangement during an $$S_N1$$ reaction?

Accepted Answer

3-chloro-3-methylpentane

Question 20

Which of the following best explains why $$CCl_4 is $$nonpolar despite having polar C–Cl bonds?

Accepted Answer

The four C–Cl bonds are symmetrically arranged, so the bond dipoles cancel.

Alkyl Halides and Nucleophilic Substitution (Chapter 6 Study Notes)

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