Deck 20: Carboxylic Acids

Question 1

Provide the structure of succinic acid.

Answer 1

HO₂C CH₂CH₂CO₂H

Question 2

Are carboxylic acids of more than 10 carbons more soluble in polar or nonpolar solvents?

Answer 2

nonpolar solvents

Question 3

The combination of a carbonyl group and a hydroxyl group on the same carbon atom is called a ________ group.

A) carbamate
B) carbonate
C) urethane
D) carboxyl
E) carboxylate

Answer 3

carboxyl

Question 4

Provide the IUPAC name for the compound shown below.

Question 5

Provide the structure of 3-nitrophthalic acid.

Question 6

Provide the structure of pent-3-ynoic acid.

Question 7

Name the compound shown below.

Question 8

Provide the name of the compound shown below.

Question 9

Provide the structure of trans-1,3-cyclohexanedicarboxylic acid.

Question 10

What is the common name for the following compound?

A) γ-hydroxyvaleric acid
B) γ-hydroxypentanoic acid
C) γ-hydroxy-γ-methylbutyric acid
D) δ-hydroxyvaleric acid

Question 11

The common name for pentanedioic acid is:

A) pimelic acid.
B) oxalic acid.
C) glutaric acid.
D) succinic acid.
E) adipic acid.

Question 12

Provide the IUPAC name for HO₂CCH₂C(CH₃)₂CH₂CH₂CO₂H.

Question 13

Draw an acetic acid dimer. Be sure to indicate the hydrogen bonds present.

Question 14

Carboxylic acids boil at considerably higher temperatures than do alcohols, ketones, or aldehydes of similar molecular weights. This is because they:

A) have a greater oxygen content.
B) are more acidic.
C) form stable hydrogen-bonded dimers.
D) are hydrophobic.
E) none of the above

Question 15

Provide the IUPAC name for the compound shown below.

Question 16

Name the compound shown below.

Question 17

Provide the structure of glutaric acid.

Question 18

Provide the structure of 3,3-dimethylheptanoic acid.

Question 19

Provide the IUPAC name for the compound shown below.

Question 20

Name the compound shown below.

Question 21

What salt results from the reaction of benzoic acid with potassium hydroxide?

Question 22

Which of the following statements is $\underline{\text{ true? }}$

A) At two pH units above the pKa, the carboxylate ion concentration exceeds the concentration of the carboxylic acid by a 100 to 1 ratio.
B) At two pH units above the pKa, the carboxylate ion concentration exceeds the concentration of the carboxylic acid by a 2 to 1 ratio.
C) At two pH units below the pKa, the carboxylate ion concentration exceeds the concentration of the carboxylic acid by a 2 to 1 ratio.
D) At two pH units below the pKa, the carboxylate ion concentration exceeds the concentration of the carboxylic acid by a 10 to 1 ratio.
E) At two pH units below the pKa the carboxylate ion concentration is equal to the carboxylic acid concentration.

Question 23

Which of the following compounds is the strongest acid?

A) p-nitrobenzoic acid
B) p-bromobenzoic acid
C) m-methylbenzoic acid
D) m-methoxybenzoic acid
E) water

Question 24

At pH 4.5, which of the following acids would be most dissociated?

A) p-nitrobenzoic acid (pK_a = 3.41)
B) acetic acid (ethanoic acid) (pK_a = 4.74)
C) hexanoic acid (pK_a = 4.88)
D) octanoic acid (pK_a = 4.89)
E) water

Question 25

The strongest dichlorobutanoic acid is:

A) 2,2-dichlorobutanoic acid.
B) 2,3-dichlorobutanoic acid.
C) 3,3-dichlorobutanoic acid.
D) 3,4-dichlorobutanoic acid.
E) 4,4-dichlorobutanoic acid.

Question 26

Provide the major organic product of the reaction shown below.

Question 27

Which of the following sequences ranks the structures below in order of increasing acidity?

A) 1 < 2 < 3
B) 2 < 3 < 1
C) 3 < 1 < 2
D) 2 < 1 < 3

Question 28

Name the salt formed from the reaction of acetic acid with ammonia.

Question 29

An unknown compound is insoluble in water but dissolves in sodium bicarbonate with a release of carbon dioxide bubbles. The compound is almost certainly:

A) a carboxylic acid.
B) an amine.
C) an aldehyde.
D) an alkyl chloride.
E) an alcohol.

Question 30

Which of the following is the strongest acid?

A) (CH₃₎₂CHCO₂H
B) CH₃CH₂CO₂H
C) CH₃OCH₂CO₂H
D) PhCH₂CO₂H
E) O₂NCH₂CO₂H

Question 31

What products result from the reaction of sodium propanoate with hydrobromic acid?

Question 32

An ether solution of PhCO₂H (A), PhNH₂ (B), and PhCH₃ (C) is extracted with aqueous NaOH. The ether layer will contain what compound(s) after the extraction?

A) A + B
B) A + C
C) B + C
D) A + B + C
E) A only

Question 33

Which of the following is the strongest acid?

A) chloroacetic acid
B) dichloroacetic acid
C) trichloroacetic acid
D) acetic acid

Question 34

List the following weak acids in order of increasing acidity (from lowest to highest.).

A) 4 < 3 < 2 < 1 < 5
B) 4 < 1 < 3 < 2 < 5
C) 5 < 2 < 3 < 1 < 4
D) 4 < 1 < 2 < 5 < 3
E) 1 < 2 < 4 < 3 < 5

Question 35

After completing the synthesis of 3-methylpentanoic acid, which of the following treatments will neutralize the mineral acids and facilitate the distribution of the organic acid from the organic layer to the aqueous extraction layer?

A) extraction with aqueous NaCl
B) extraction with ether
C) extraction with aqueous NaHCO₃
D) extraction with water
E) extraction with dilute aqueous HCl

Question 36

In the propanoate ion,

A) both the carbon-oxygen bonds are the same length.
B) the carbon-oxygen double bond is shorter.
C) the carbon-oxygen double bond is longer.
D) one of the oxygen atoms bears a -1 charge.
E) the carbon atom bears a -1 charge.

Question 37

Provide the structure of zinc undecanoate, a major component in several athlete's foot medications.

Question 38

Why are the OH groups of carboxylic acids more acidic than alcohols?

A) resonance stabilization of the carboxylate ion
B) inductive electron donating by the carbonyl oxygen
C) reduced hydrogen bonding capacity
D) because they have lower pKa values
E) None of the above - carboxylic acids are not more acidic than alcohols.

Question 39

Which of the following is the strongest acid?

A) acetic acid
B) chloroacetic acid
C) bromoacetic acid
D) fluoroacetic acid

Question 40

Using acid-base extractions, how might you purify a crude sample of benzoic acid?

Question 41

What compound is produced when cyclohexene is treated with concentrated KMnO₄?

A) hexanoic acid
B) adipic acid
C) cyclohexanecarboxylic acid
D) benzoic acid
E) succinic acid

Question 42

In the mass spectrum of 3-methylhexanoic acid, predict the mass of the fragment
resulting from a McLafferty rearrangement.

Question 43

An acid which could $\underline{\text{ not }}$ be prepared from an organic halide by carboxylation of the Grignard reagent is:

A) benzoic acid.
B) 2,2-dimethylpropanoic acid.
C) propanoic acid.
D) 4-oxocyclohexanecarboxylic acid.
E) 2-methylbutanoic acid.

Question 44

How does the O-H stretch in the IR spectrum of a carboxylic acid differ from the O-H stretch of an alcohol?

Question 45

2-Phenylethanol yields what acid upon treatment with cold chromic acid?

Question 46

Provide the major organic product of the following reaction.

Question 47

In the mass spectrum of pentanoic acid, the base peak occurs at m/z ________.

A) 102
B) 101
C) 85
D) 73
E) 60

Question 48

What two features are prominent in the infrared spectrum of a carboxylic acid?

Question 49

1-Hexanol reacts with chromic acid to yield what product?

Question 50

Provide the major organic product of the reaction shown below.

Question 51

Which of the following statements is $\underline{\text{ true?}}$

A) The carbonyl carbon in a carboxylic acid does not give a ¹³C signal in a ¹³C-NMR spectrum.
B) The carbonyl carbon in a carboxylic acid gives a ¹³C signal in the same region as a carbonyl carbon from a ketone or aldehyde - in the range of 200 ppm.
C) The carbonyl carbon of a carboxylic acid splits a proton signal into a doublet in an H-NMR spectrum.
D) The carbonyl carbon in a carboxylic acid gives a ¹³C signal in the same region as a carbonyl carbon from an ester or amide in the range of 150 to 180 ppm.
E) The carbonyl carbon in a carboxylic acid cannot be distinguished from an aromatic carbon because they both give signals in the range of 110 to 130 ppm.

Question 52

Carboxylic acids can be made from Grignards by treating the Grignard reagents with:

A) carbon monoxide.
B) esters.
C) aldehydes.
D) diborane.
E) carbon dioxide.

Question 53

Deduce a reasonable structure for the compound which exhibits the following spectroscopic data.
C₅H₉ClO₂: IR: 2700-3400 cm^-1 (broad), 1710 cm^-1; ¹H NMR: - 1.40 (6H, singlet), 3.60 (2H, singlet), 10.1 (1H, singlet) ppm.

Question 54

Which of the following must be converted into a carboxylic acid through nitrile hydrolysis rather than through a Grignard synthesis with Mg/ether followed with dry CO₂ and work-up with H₃O⁺?

Question 55

Provide the major organic product of the following reaction.

Question 56

Where would one expect to find the ¹H NMR signal for the carboxyl group's hydrogen in propanoic acid?

A) δ 4.1 - 5.6 ppm
B) δ 10 - 13 ppm
C) δ 8 - 9 ppm
D) δ 6.1 - 7.8 ppm
E) δ 9.5 - 10 ppm

Question 57

Provide the major organic product of the following reaction.

Question 58

What compound is produced when (CH₃)₂CHCH₂Br is subjected to the following sequence of steps? 1. Mg, Et₂O 2. CO₂

A) 2-methylpropanoic acid
B) 3-methylpropanoic acid
C) 2-methylbutanoic acid
D) 3-methylbutanoic acid
E) 2-methylhexanoic acid

Question 59

An acid which could $\underline{\text{ not }}$ be prepared by the reaction of an organic halide with cyanide ion followed by acid hydrolysis of the nitrile is:

A) propanoic acid.
B) phenylacetic acid.
C) acetic acid.
D) (CH₃₎₃CCO₂H.
E) CH₃(CH₂)₁₄CO₂H.

Question 60

Provide the major organic product of the reaction shown below.

Question 61

Provide the major organic product of the following reaction sequence.

Question 62

Which sequence of steps below describes the best synthesis of 5-oxohexanoic acid starting with 1-methylcyclopentan-1-ol?

A) 1. Conc. KMnO₄
2. Dry gaseous HBr
3. mg/ether
4. CO₂
B) 1. H₂SO₄ and heat
2. Conc. KMnO₄
C) 1. Conc. KMnO₄
2. CH₃MgBr/ ether
3. H₃O⁺
D) 1. H₂SO₄ and heat
2. O₃
3. (CH₃)₂S
4. PCC
E) 1. H₂SO₄ and heat
2. Conc. KMnO₄
3. LiAlH₄
4. H₃O⁺

Question 63

Suggest a sequence of synthetic steps through which p-toluic acid can be prepared from toluene.

Question 64

Provide the sequence of reagents needed to accomplish the conversion below.

Question 65

Provide the major organic product of the following reaction.

Question 66

Provide the major organic product of the following reaction sequence.

Question 67

What two alkenes, which contain only one double bond, yield exclusively propanoic acid upon oxidation with hot concentrated KMnO₄?

Question 68

Provide the major organic product of the reaction shown below.

Question 69

Provide the major organic product of the following reaction.
HC(OCH₂CH₃)₃

Question 70

Provide the major organic product of the reaction shown below.

Question 71

Provide the major organic product of the following reaction sequence.

Question 72

Suggest a sequence of synthetic steps through which phenylacetic acid can be prepared from toluene and in which Grignard chemistry is employed.

Question 73

Propose a reasonable synthetic route to prepare cyclohexylacetic acid from methylenecyclohexane.

Question 74

Provide the major organic product of the following reaction.

Question 75

Provide the major organic product of the reaction shown below.

Question 76

Draw a Fischer projection of the product which results when (R)-2-bromobutane is treated with the following sequence of reagents: 1. CN^-, 2. H₃O⁺, and 3. CH₂N₂.

Question 77

Hept-3-yne yields what acids upon treatment with concentrated permanganate of ozone followed by water?

Question 78

Suggest a sequence of synthetic steps through which phenylacetic acid can be prepared from toluene via phenylacetonitrile.

Question 79

Provide the major organic product of the following reaction sequence.

Question 80

2-Phenylethanol yields what acid upon treatment with hot chromic acid or permanganate?