Question 1

Which of the following statements best explains why alkyl halides are reactive toward nucleophilic substitution reactions?

Accepted Answer

The carbon-halogen bond is polar, so the carbon has a partial positive charge and can be attacked by a nucleophile.

Question 2

Which of the following is the correct IUPAC name for the compound with the structure $\mathrm{CH_3CH_2CH_2CH_2Br}$?

Accepted Answer

1-bromobutane

Question 3

Which type of alkyl halide is most reactive in an $\mathrm{S_N1}$ reaction mechanism?

Accepted Answer

Tertiary alkyl halide

Question 4

What is the major product when 2-bromopropane reacts with sodium hydroxide ($\mathrm{NaOH}$) in acetone?

Accepted Answer

2-propanol via $\mathrm{S_N2}$ substitution

Question 5

Which of the following solvents will increase the rate of an $\mathrm{S_N2}$ reaction?

Accepted Answer

Dimethylformamide (DMF)

Question 6

A chemist wants to selectively brominate the allylic position of cyclohexene. Which reagent should be used?

Accepted Answer

N-bromosuccinimide (NBS) with light

Question 7

Which of the following best describes the stereochemical outcome of an $\mathrm{S_N2}$ reaction at a chiral center?

Accepted Answer

Inversion of configuration (Walden inversion)

Question 8

Which of the following is a geminal dihalide?

Accepted Answer

$\mathrm{CH_2Br_2}$

Question 9

Why do tertiary alkyl halides not undergo $\mathrm{S_N2}$ reactions?

Accepted Answer

The nucleophile cannot approach due to steric hindrance from three alkyl groups.

Question 10

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

Accepted Answer

$\mathrm{Cl^-}$

Question 11

Which factor most increases the boiling point of alkyl halides?

Accepted Answer

Increased London dispersion forces due to larger halogen atoms

Question 12

Which of the following statements about nucleophilicity is correct?

Accepted Answer

Nucleophilicity increases from right to left across the periodic table.

Question 13

What is the expected product when tert-butyl bromide reacts with water?

Accepted Answer

tert-Butyl alcohol via $\mathrm{S_N1}$ mechanism

Question 14

Which of the following is true regarding the $\mathrm{S_N1}$ reaction mechanism?

Accepted Answer

It proceeds via a carbocation intermediate and often leads to racemization.

Question 15

Which of the following compounds is denser than water?

Accepted Answer

Chloroform ($\mathrm{CHCl_3}$)

Question 16

Which of the following best describes the effect of polar protic solvents on nucleophilicity?

Accepted Answer

They decrease nucleophilicity by solvating nucleophiles through hydrogen bonding.

Question 17

Which rearrangement is most likely to occur during an $\mathrm{S_N1}$ reaction of 1-bromo-2-methylbutane?

Accepted Answer

Methyl shift to form a more stable tertiary carbocation

Question 18

Which of the following is a vicinal dihalide?

Accepted Answer

$\mathrm{CH_2ClCH_2Cl}$

Question 19

Which of the following best explains why $\mathrm{S_N2}$ reactions proceed faster in aprotic solvents?

Accepted Answer

Aprotic solvents do not solvate nucleophiles, allowing them to remain reactive.

Question 20

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

$\mathrm{CH_3CH_2CH(CH_3)CH_2Br}$

Accepted Answer

4-bromo-2-methylpentane

Alkyl Halides: Structure, Nomenclature, and Classification

Study Guide - Practice Questions