Question 1

Which functional group is most likely present in a compound that shows a strong IR absorption near $1700\ 	ext{cm}^{-1}$?

Accepted Answer

Carbonyl

Question 2

Which of the following carboxylic acid derivatives is the most reactive toward nucleophilic acyl substitution?

Accepted Answer

Acyl chloride

Question 3

What is the correct order of boiling points for the following compounds: amide, carboxylic acid, ester, aldehyde?

Accepted Answer

Amide > carboxylic acid > ester > aldehyde

Question 4

Which of the following statements best explains why acyl chlorides are more reactive than amides in nucleophilic acyl substitution?

Accepted Answer

Chloride is a weaker base and a better leaving group than amide

Question 5

In a nucleophilic acyl substitution, what determines which group is eliminated from the tetrahedral intermediate?

Accepted Answer

The group with the lowest basicity

Question 6

Which of the following reactions is an example of Fischer esterification?

Accepted Answer

$\ce{RCOOH} + \ce{R'OH} \xrightarrow{H^+} \ce{RCOOR'} + \ce{H2O}$

Question 7

Which of the following best describes the mechanism of nucleophilic acyl substitution under basic conditions?

Accepted Answer

Nucleophilic addition to the carbonyl is followed by loss of a leaving group

Question 8

Which of the following is the best leaving group in nucleophilic acyl substitution?

Accepted Answer

$\ce{Cl^-}$

Question 9

A student hydrolyzes methyl acetate labeled with $^{18}\mathrm{O}$ in the ethoxy group under acidic conditions. After mild acidification, where will the $^{18}\mathrm{O}$ label be found?

Accepted Answer

In the methanol product

Question 10

Which of the following best explains why acid-catalyzed ester hydrolysis is reversible, but base-promoted ester hydrolysis is not?

Accepted Answer

The carboxylate ion formed under basic conditions is unreactive toward nucleophilic attack

Question 11

Which of the following sets of reagents would convert a primary alcohol to an acyl chloride via a carboxylic acid intermediate?

Accepted Answer

1. $\ce{TsCl}$/pyridine 2. $\ce{NaCN}$ 3. $\ce{H3O^+}/\Delta$ 4. $\ce{SOCl2}$/pyridine

Question 12

Which of the following carboxylic acid derivatives would be most readily hydrolyzed by aqueous base?

Accepted Answer

Acyl chloride

Question 13

Which of the following best describes the role of the second equivalent of amine in the reaction of an acyl chloride with excess amine?

Accepted Answer

It acts as a base to neutralize the HCl formed

Question 14

Which of the following is the correct IUPAC name for the compound $\ce{CH3CH2CH2COCl}$?

Accepted Answer

Butanoyl chloride

Question 15

Which of the following best explains why amides have higher boiling points than esters?

Accepted Answer

Amides can form stronger hydrogen bonds due to the presence of N-H bonds

Question 16

Which of the following is the correct product for the reaction of acetic anhydride with ethanol?

Accepted Answer

Ethyl acetate and acetic acid

Question 17

Which of the following best describes the effect of electron-withdrawing groups on the acidity of dicarboxylic acids?

Accepted Answer

They lower the first $pK_a$ by stabilizing the conjugate base

Question 18

Which of the following is the correct IUPAC name for the compound shown: $\ce{CH3CH=CHCH2CHO}$?

Accepted Answer

3-pentenal

Question 19

Which of the following best explains why anhydrides are more reactive than esters but less reactive than acyl chlorides?

Accepted Answer

The leaving group of anhydrides is a carboxylate ion, which is a weaker base than chloride but stronger than alkoxide

Study Notes: Carbonyl Compounds and Their Reactions

Study Guide - Practice Questions

Study Guide - Flashcards