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

Question 1

Which of the following best describes the polar nature of the carbon-halogen bond in alkyl halides?

Accepted Answer

The halogen is more electronegative than carbon, resulting in a partial negative charge on the halogen and a partial positive charge on carbon.

Question 2

Which of the following is the best leaving group for an $$S_N2$$ reaction?

Accepted Answer

$$\mathrm{I^-}$$

Question 3

In an $$S_N2$$ reaction, which factor most significantly increases the reaction rate?

Accepted Answer

Using a polar aprotic solvent such as DMSO.

Question 4

Which of the following statements about $$S_N1$$ and $$S_N2$$ mechanisms is correct?

Accepted Answer

$$S_N1$$ reactions are favored by polar protic solvents.

Question 5

Which of the following nucleophiles is the strongest in a polar aprotic solvent?

Accepted Answer

$$\mathrm{CH_3O^-}$$

Question 6

Which product is favored in the E2 elimination of 2-bromobutane with a strong base?

Accepted Answer

trans-2-butene

Question 7

What is the rate law for an $$S_N2$$ reaction?

Accepted Answer

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

Question 8

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

Accepted Answer

tert-butyl bromide

Question 9

Which of the following best explains why $$E2$$ eliminations favor the more substituted alkene (Zaitsev's rule)?

Accepted Answer

More substituted alkenes are more stable due to hyperconjugation and alkyl group electron donation.

Question 10

Which of the following solvents would most likely increase the rate of an $$S_N1$$ reaction?

Accepted Answer

Water

Question 11

Which of the following is NOT a characteristic of an $$S_N2$$ reaction?

Accepted Answer

Carbocation intermediate formation.

Question 12

A secondary alkyl halide is treated with a strong base. Which reaction pathway is most likely?

Accepted Answer

E2

Question 13

Which of the following best describes the effect of steric hindrance on $$S_N2$$ reactions?

Accepted Answer

Steric hindrance decreases the rate of $$S_N2$$ reactions.

Question 14

Which of the following is the best description of a nucleophile?

Accepted Answer

A species that donates an electron pair.

Question 15

Which of the following statements about the E1 and E2 mechanisms is correct?

Accepted Answer

E2 reactions are concerted and require a strong base.

Question 16

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

Accepted Answer

$$\mathrm{OH^-}$$

Question 17

Which of the following best explains why polar aprotic solvents increase the rate of $$S_N2$$ reactions?

Accepted Answer

They do not solvate anions well, making the nucleophile more reactive.

Question 18

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

Accepted Answer

2-pentene

Question 19

Which of the following best describes the difference between $$S_N1$$ and $$S_N2$$ reactions regarding stereochemistry?

Accepted Answer

$$S_N2$$ reactions give inversion of configuration, while $$S_N1$$ reactions give racemization.

Question 20

Which of the following alkyl halides will react slowest in an $$S_N2$$ reaction?

Accepted Answer

tert-Butyl bromide

Reactions of Alkyl Halides: Nucleophilic Substitution (S extsubscript{N}1/S extsubscript{N}2) & Elimination (E1/E2/E1cb)

Study Guide - Practice Questions