Question 1

Which of the following statements best explains why tertiary alkyl halides do not undergo $$S_N2$$ reactions efficiently?

Accepted Answer

Tertiary alkyl halides are sterically hindered, preventing backside attack by the nucleophile required for $$S_N2.$$

Question 2

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

Accepted Answer

$$	ext{rate} = k[RX][Nu^-]$$

Question 3

A student reacts 2-bromopropane with sodium hydroxide in water. Which mechanism is most likely and what is the major product?

Accepted Answer

$$S_N1$$; 2-propanol

Question 4

Which of the following best describes Zaitsev’s Rule in elimination reactions?

Accepted Answer

The most substituted alkene is formed preferentially.

Question 5

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

Accepted Answer

$$Br^-$$

Question 6

What is the expected product when 2-methyl-2-butanol is treated with concentrated $$H_2SO_4$$ and heated?

Accepted Answer

2-methyl-2-butene

Question 7

Which of the following factors increases the rate of an $$S_N1$$ reaction?

Accepted Answer

Using a more stable carbocation intermediate

Question 8

Which of the following statements about the $$E2$$ reaction mechanism is correct?

Accepted Answer

It is a concerted reaction where the base removes a proton as the leaving group departs.

Question 9

Which of the following alcohols will dehydrate most rapidly under acidic conditions?

Accepted Answer

2-methyl-2-propanol

Question 10

A reaction of 3,3-dimethyl-2-butanol with $$HCl$$ gives 2-chloro-2,3-dimethylbutane as the major product. What mechanistic feature explains this outcome?

Accepted Answer

Methyl shift

Question 11

Which of the following is true regarding the stereochemistry of $$S_N2$$ reactions?

Accepted Answer

They invert the configuration at the reaction center.

Question 12

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

Accepted Answer

Dimethyl sulfoxide (DMSO)

Question 13

Which of the following statements about the deuterium isotope effect in $$E2$$ reactions is correct?

Accepted Answer

The reaction rate is slower when the leaving hydrogen is replaced by deuterium.

Question 14

Which of the following best describes the geometry required for an $$E2$$ elimination to occur?

Accepted Answer

The leaving group and the hydrogen must be anti periplanar.

Question 15

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

Accepted Answer

Tertiary alkyl bromide

Question 16

Which of the following is a correct statement about the product distribution in the dehydration of 2-methyl-2-butanol?

Accepted Answer

2-methyl-2-butene is the major product due to Zaitsev’s rule.

Question 17

Which of the following nucleophiles is most likely to favor substitution over elimination when reacting with a primary alkyl halide?

Accepted Answer

$$N_3$$^-$$

Question 18

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

$$\mathrm{BrCH_2CH_2CH(CH_3$)CH_2CH_3}$$

Accepted Answer

1-bromo-3-methylpentane

Question 19

Which of the following best explains why $$S_N1$$ reactions often produce racemic mixtures from chiral starting materials?

Accepted Answer

The carbocation intermediate is planar, allowing attack from either side.

Question 20

Which of the following is most likely to undergo rearrangement during an $$S_N1 or$$ $$E1$$ reaction?

Accepted Answer

A secondary carbocation intermediate adjacent to a tertiary carbon

Reactions of Alkyl Halides: Nucleophilic Substitutions and Eliminations

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