Question 1

Which of the following statements best explains why carboxylic acids have higher boiling points than alcohols of similar molecular weight?

Accepted Answer

Carboxylic acids form stable, hydrogen-bonded dimers, which require more energy to break apart.

Question 2

What is the IUPAC name for the following compound: $\mathrm{CH_3CH_2CH_2COOH}$?

Accepted Answer

Butanoic acid

Question 3

Which of the following acids is expected to have the lowest p$K_a$ value?

Accepted Answer

Trichloroacetic acid ($\mathrm{CCl_3COOH}$)

Question 4

A student wants to synthesize benzoic acid from toluene. Which reagent would be most effective for this transformation?

Accepted Answer

Hot, concentrated $\mathrm{KMnO_4}$

Question 5

Which of the following best describes the resonance stabilization of the acetate ion?

Accepted Answer

The negative charge is delocalized equally over both oxygen atoms.

Question 6

Which of the following methods will increase the number of carbon atoms in a molecule by one?

Accepted Answer

Carboxylation of a Grignard reagent with $\mathrm{CO_2}$

Question 7

Which of the following statements about the acidity of carboxylic acids is correct?

Accepted Answer

Electron-withdrawing groups increase acidity, especially when located ortho or para to the carboxyl group.

Question 8

Which of the following is a correct description of the IR spectrum of a carboxylic acid?

Accepted Answer

A strong, broad O–H stretch from $2500$ to $3500\ \mathrm{cm}^{-1}$ and a strong C=O stretch near $1710\ \mathrm{cm}^{-1}$.

Question 9

A solution contains a carboxylic acid with a p$K_a$ of $4.8$. At what pH will the acid be mostly dissociated?

Accepted Answer

At pH $> 4.8$

Question 10

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

$\mathrm{HOOCCH_2CH_2COOH}$

Accepted Answer

Butanedioic acid

Question 11

Which of the following best describes the mechanism of Fischer esterification?

Accepted Answer

Protonation of the carbonyl, nucleophilic attack by alcohol, loss of water, and deprotonation to form the ester.

Question 12

Which of the following reagents can be used to convert a carboxylic acid to its acid chloride?

Accepted Answer

Thionyl chloride ($\mathrm{SOCl_2}$)

Question 13

Which of the following statements about the solubility of carboxylic acids is correct?

Accepted Answer

Carboxylic acids with more than 10 carbon atoms are nearly insoluble in water.

Question 14

Which of the following is a correct product of the reaction between a carboxylic acid and diazomethane ($\mathrm{CH_2N_2}$)?

Accepted Answer

A methyl ester and nitrogen gas

Question 15

Which of the following best explains why cis double bonds in fatty acids lower the melting point?

Accepted Answer

Cis double bonds introduce kinks, preventing tight packing of molecules.

Question 16

Which of the following is a correct method for synthesizing an amide from a carboxylic acid?

Accepted Answer

React the acid with an amine to form an ammonium carboxylate salt, then heat to form the amide.

Question 17

Which of the following statements about the extraction of carboxylic acids is correct?

Accepted Answer

The carboxylate salt is more soluble in the aqueous phase than the organic phase.

Question 18

Which of the following is a correct statement about the reduction of carboxylic acids?

Accepted Answer

Carboxylic acids can be reduced to primary alcohols using $\mathrm{LiAlH_4}$.

Carboxylic Acids: Structure, Properties, and Reactions

Study Guide - Practice Questions