Deck 14: Carboxylic Acids and Nitriles

Question 1

What is the correct IUPAC name of the following compound?

A) 4,5-Dimethylcyclohexanecarboxylic acid
B) 1,2-Dimethylcyclohexanecarboxylic acid
C) 3,4-Dimethylcyclohexanoic acid
D) 3,4-Dimethylcyclohexanecarboxylic acid

Answer 1

3,4-Dimethylcyclohexanecarboxylic acid

Question 2

What two strong absorptions are characteristic of the IR spectrum of carboxylic acids?

A) A C=O absorption at 1710 cm^-1 and an O-H absorption at 2500-3500 cm^-1.
B) A C=O absorption at 1600 cm^-1 and an O-H absorption at 2500-3000 cm^-1.
C) A C=O absorption at 1710 cm^-1 and a C-H absorption at 3000 cm^-1.
D) A C-O absorption at 1500 cm^-1 and an O-H absorption at 2500-3500 cm^-1.

Answer 2

A C=O absorption at 1710 cm^-1 and an O-H absorption at 2500-3500 cm^-1.

Question 3

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

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

Answer 3

Physical property = solubility differences; reaction type = acid-base reaction

Question 4

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

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

Question 5

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

Question 6

Where do the two noteworthy peaks of carboxylic acids appear in¹HNMR spectra?

A) Between 6 and 9 ppm for the OH proton and 1-1.5 ppm for the protons on the a carbon to the carboxy group.
B) Between 10 and 12 ppm for the OH proton and 1-1.5 ppm for the protons on the a carbon to the carboxy group.
C) Between 10 and 12 ppm for the OH proton and 2-2.5 ppm for the protons on the a carbon to the carboxy group.
D) Between 6 and 9 ppm for the OH proton and 2-2.5 ppm for the protons on the a carbon to the carboxy group.

Question 7

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 carboxylic acid issp³ hybridized and has a lower percent s-character that shortens the C-O bond in the carboxylic acid.
B) The carbon in the carboxylic acid issp² hybridized and has a higher percent s-character that shortens the C-O bond in the carboxylic acid.
C) The carbon in the carboxylic acid issp hybridized and has a higher percent s-character that shortens the C-O bond in the carboxylic acid.
D) The carbon in the alcohol issp² hybridized and has a higher percent s-character that lengthens the C-O bond in the alcohol.

Question 8

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

Question 9

What is the correct IUPAC name of the following compound?

A) 3,5,5-Trimethylcyclohexanoic acid
B) 3,5,5-Trimethylcyclohexanecarboxylic acid
C) 3,3,5-Trimethylcyclohexanecarboxylic acid
D) 3,3,5-Trimethylcyclohexanoic acid

Question 10

Which of the following reagents can accomplish the transformation below?

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

Question 11

What is the correct IUPAC name of the following compound?

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