Deck 19: Carboxylic Acids and the Acidity of the O-H Bond

Question 1

Arrange the following compounds in order of increasing water solubility, putting the least soluble compound first.

A)I < II < III < IV
B)II < I < III < IV
C)I < III < II < IV
D)IV < II < III < I

Answer 1

IV < II < III < I

Question 2

Why is pure acetic acid often called glacial acetic acid?

A)Because it freezes just below 0°C, forming white crystals.
B)Because it freezes just below 100°C, forming white crystals.
C)Because it freezes just below room temperature, forming white crystals.
D)Because it freezes just above room temperature, forming white crystals.

Answer 2

Because it freezes just below room temperature, forming white crystals.

Question 3

What two groups make up the carboxylic acid group (RCOOH)?

A)Carbon dioxide and hydrogen
B)Carbonyl and hydroxyl
C)Carbon monoxide and hydroxyl
D)Carbonyl oxide and hydrogen

Answer 3

Carbonyl and hydroxyl

Question 4

Which of the following is the structure of oxalic acid?

A)I
B)II
C)III
D)IV

Question 5

Which of the following is the correct IUPAC name for the following structure?

A)Potassium propanoate
B)Butanoic potassium
C)Potassium propanoic
D)Potassium butanoate

Question 6

Why is the C-O single bond of a carboxylic acid shorter than the C-O single bond of an alcohol?

A)The carbon in the alcohol is sp² hybridized and has a higher percent s-character that lengthens the C-O bond in the alcohol.
B)The carbon in the carboxylic acid is sp³ hybridized and has a lower percent s-character that shortens the C-O bond in the carboxylic acid.
C)The carbon in the carboxylic acid is sp hybridized and has a higher percent s-character that shortens the C-O bond in the carboxylic acid.
D)The carbon in the carboxylic acid is sp² hybridized and has a higher percent s-character that shortens the C-O bond in the carboxylic acid.

Question 7

What is the common name of the following compound?

A)a-Methylbutyric acid
B)a-Propylpropionic acid
C)a-Methylvaleric acid
D)a-Methylcaproic acid

Question 8

What is the other product formed in the oxidation of the following terminal alkyne?

A)HCOOH
B)HCOH
C)CO₂
D)CO

Question 9

What is the correct IUPAC name of the following compound?

A)(E)-2-Hexenoic acid
B)(Z)-2-Hexenoic acid
C)(E)-4-Hexenoic acid
D)(Z)-4-Hexenoic acid

Question 10

Arrange the following compounds in order of increasing boiling point, putting the compound with the lowest boiling point first.

A)I < II < III < IV
B)I < IV < II < III
C)III < II < IV < I
D)II < IV < I < III

Question 11

Which of the following cannot be the starting material for the following reaction?

A)I
B)II
C)III
D)IV

Question 12

What is the correct IUPAC name of the following compound?

A)2-Methoxypentanoic acid
B)2-Methoxybutanoic acid
C)4-Methoxybutanoic acid
D)4-Methoxypentanoic acid

Question 13

What is the hybridization of the carbon atom in a carboxy group?

A)sp
B)sp²
C)sp³
D)p

Question 14

What is the correct IUPAC name of the following compound?

A)2-sec-Butyl-4,4-dimethylnonanoic acid
B)4,4-Dimethyl-2-isobutylnonanoic acid
C)4,4-Dimethyl-2-sec-butylnonanoic acid
D)2-Isobutyl-4,4-dimethylnonanoic acid

Question 15

Which of the following structures is the major contributor to the resonance hybrid of the phenoxide anion?

A)I
B)II
C)III
D)IV

Question 16

What is the correct IUPAC name of the following compound?

A)4-Isopropyl-3-methylbutanoic acid
B)2,4-Dimethylhexanoic acid
C)3,5-Dimethylhexanoic acid
D)3,5-Dimethy-1-hexanoic acid

Question 17

What is the common name of the following compound?

A)b,b-Dimethyl-a-fluorobutyric acid
B)a-Fluoro-b,b-dimethylbutyric acid
C)a-Fluoro-b,b,b-trimethylpropionic acid
D)a-Fluoro-b,b,b-trimethylbutyric acid

Question 18

Which of the following reagents can accomplish the transformation below?

A)PCC, CH₂Cl₂
B)[1] LiAlH₄, THF; [2] H₂O
C)[1] O₃; [2] H₂O
D)K₂Cr₂O₇, H₂SO₄, H₂O

Question 19

In the presence of strong acids, which of the oxygen atoms on the carboxyl group is preferentially protonated and why?

A)Protonation occurs at the carbonyl oxygen because the resulting conjugate acid is stabilized by resonance.
B)Protonation occurs at the carbonyl oxygen because the resulting conjugate base is stabilized by the inductive effect.
C)Protonation occurs at the hydroxyl oxygen because the resulting conjugate acid is stabilized by resonance.
D)Protonation occurs at the hydroxyl oxygen because the resulting conjugate base is stabilized by the inductive effect.

Question 20

Which of the following is the most polar organic compound?

A)CH₃CH₂CH₂CH₃
B)CH₃CH₂CHO
C)CH₃CH₂CH₂OH
D)CH₃COOH

Question 21

What is the overall charge of the amino acid, alanine, at pH = 7?

A)+ 1
B)- 1
C)No overall charge
D)+ 2

Question 22

Arrange the following compounds in order of increasing acidity, putting the least acidic first.

A)I < II < III < IV
B)IV < III < II < I
C)III < IV < II < I
D)IV < II < III < I

Question 23

What would happen if a mixture of benzoic acid (C₆H₅COOH) and NaCl is added to a separatory funnel containing H₂O and CH₂Cl₂?

A)The benzoic acid would dissolve in the water layer and the NaCl would dissolve in the organic layer.
B)The benzoic acid would dissolve in the organic layer and the NaCl would dissolve in the water layer.
C)Both benzoic acid and NaCl would dissolve in the organic layer.
D)Both benzoic acid and NaCl would dissolve in the water layer.

Question 24

Rank the following compounds in order of increasing acidity, putting the least acidic first.

A)II < III < I < IV
B)II < I < III < IV
C)IV < III < I < II
D)IV < I < II < III

Question 25

What is the overall charge of the amino acid, alanine, at pH = 10?

A)+ 1
B)- 1
C)No overall charge
D)- 2

Question 26

Rank the following compounds in order of increasing acidity, putting the least acidic compound first.

A)III < I < II < IV
B)IV < I < II < III
C)III < II < I < IV
D)II < IV < I < III

Question 27

Which of the following compounds is least basic?

A)I
B)II
C)III
D)IV

Question 28

What physical property and reaction type are used by extraction as useful techniques to separate and purify mixtures of compounds?

A)Physical property = solubility differences; reaction type = acid-base reaction.
B)Physical property = boiling point; reaction type = acid-base reaction.
C)Physical property = solubility differences; reaction type = oxidation-reduction.
D)Physical property = density; reaction type = oxidation-reduction.

Question 29

Which of the following bases are strong enough to significantly deprotonate ethanol, CH₃CH₂OH (pKa = 16)?

A)NaOCH₃
B)NaOH
C)NaH
D)NaOCH₂CH₃

Question 30

Rank the following compounds in order of decreasing acidity, putting the most acidic first.

A)IV > III > II > I
B)IV > I > III > II
C)I > II > III > IV
D)IV > II > III > I

Question 31

Which of the following compounds is most basic?

A)I
B)II
C)III
D)IV

Question 32

What would happen if a mixture of benzoic acid and cyclohexanol dissolved in CH₂Cl₂ is treated with aqueous NaOH solution?

A)Benzoic acid would remain in the CH₂Cl₂ layer, and cyclohexanol would dissolve in the aqueous layer.
B)Benzoic acid would dissolve in the aqueous layer while cyclohexanol would remain in the CH₂Cl₂ layer.
C)The salt of benzoic acid would dissolve in the aqueous layer while cyclohexanol would remain in the CH₂Cl₂ layer.
D)The salt of benzoic acid would remain in the CH₂Cl₂ layer while cyclohexanol would dissolve in the aqueous layer.

Question 33

Rank the labeled protons (H_a-H_d) in order of increasing acidity, starting with the least acidic.

A)Ha < Hb < Hc < Hd
B)Hb < Hc < Ha < Hd
C)Hd < Ha < Hc < Hb
D)Hb < Hc < Hd < Ha

Question 34

As applied to the chemistry of amino acids, what is the definition for the isoelectric point?

A)The pH at which the amino acid exists primarily in its acidic form.
B)The pH at which the amino acid exists primarily in its basic form.
C)The pH at which the amino acid exists as a mixture of isomers.
D)The pH at which the amino acid exists primarily in its neutral form.

Question 35

Rank the following compounds in order of decreasing acidity, putting the most acidic first.

A)III > IV > I > II
B)IV > III > I > II
C)I > II > III > IV
D)IV > III > II > I

Question 36

What is the overall charge of the amino acid, alanine, at pH = 2?

A)+ 1
B)- 1
C)No overall charge
D)+ 2