,Verified CHEM 219 Module 4 Exam Principles of
Organic Chemistry w/Lab | Portage (2026–2027)
1. What is the correct IUPAC name for the compound shown below?
CH₃-CH₂-CH(OH)-CH₂-CH₂-CH₃
A) 3-hexanol
B) 2-hexanol
C) 4-hexanol
D) Hexan-3-ol
Correct Answer: 3-hexanol
Rationale: The longest carbon chain contains six carbons (hexane). The hydroxyl (-OH) group is the
principal functional group, taking the suffix "-ol". Numbering the chain from the end closest to the -
OH gives the hydroxyl group at carbon 3. Therefore, the correct IUPAC name is 3-hexanol. The other
options represent incorrect locants or names.
2. Which of the following alcohols is classified as a secondary alcohol?
A) 2-methyl-2-propanol
B) 2-butanol
C) 1-propanol
D) Cyclohexanol
Correct Answer: 2-butanol
Rationale: A secondary alcohol has the hydroxyl-bearing carbon bonded to two other carbon atoms.
In 2-butanol (CH₃-CH(OH)-CH₂-CH₃), carbon 2 is bonded to two carbon groups (a methyl and an ethyl),
making it secondary. 2-methyl-2-propanol and cyclohexanol are tertiary, and 1-propanol is primary.
3. Which of the following correctly explains why alcohols have higher boiling points than alkanes of
similar molecular weight?
,A) Alcohols have stronger London dispersion forces.
B) Alcohols can form hydrogen bonds with each other.
C) Alcohols are more polarizable than alkanes.
D) Alcohols have higher molecular weights.
Correct Answer: Alcohols can form hydrogen bonds with each other.
Rationale: Alcohols contain an O-H bond, allowing them to form intermolecular hydrogen bonds,
which are strong dipole-dipole interactions. These hydrogen bonds require significant energy to
overcome, leading to higher boiling points. Alkanes only exhibit weak London dispersion forces,
resulting in much lower boiling points.
4. What is the product of the acid-catalyzed dehydration of 2-butanol?
A) 1-butene
B) 2-butene
C) Butane
D) 2-butanone
Correct Answer: 2-butene
Rationale: Acid-catalyzed dehydration of an alcohol follows Zaitsev's rule, where the more substituted
alkene is the major product. Dehydration of 2-butanol (CH₃-CH(OH)-CH₂-CH₃) gives 2-butene (CH₃-
CH=CH-CH₃) as the major product, with 1-butene as a minor product. The reaction proceeds through a
carbocation intermediate.
5. Which of the following reagents would be used to convert a primary alcohol to an aldehyde?
A) KMnO₄ (hot, concentrated)
B) K₂Cr₂O₇ (Jones reagent)
C) PCC (pyridinium chlorochromate)
D) H₂SO₄ (concentrated)
, Correct Answer: PCC (pyridinium chlorochromate)
Rationale: PCC is a mild oxidizing agent that selectively oxidizes primary alcohols to aldehydes.
Stronger oxidizing agents like KMnO₄ or Jones reagent (K₂Cr₂O₇/H₂SO₄) will further oxidize the
aldehyde to a carboxylic acid. PCC stops at the aldehyde stage and is therefore the reagent of choice
for this transformation.
6. Which of the following is the correct structure for 3-methyl-2-butanol?
A) CH₃-CH(OH)-CH(CH₃)-CH₃
B) CH₃-CH(CH₃)-CH(OH)-CH₃
C) (CH₃)₂CH-CH₂-CH₂OH
D) CH₃-CH(OH)-CH₂-CH₂-CH₃
Correct Answer: CH₃-CH(OH)-CH(CH₃)-CH₃
Rationale: The parent chain is butanol (four carbons). A methyl group is attached to carbon 3, and the
hydroxyl group is on carbon 2. Numbering from the end closest to the -OH gives the lowest locant for
the hydroxyl. The structure CH₃-CH(OH)-CH(CH₃)-CH₃ matches this description.
7. In the Williamson ether synthesis, an alkoxide ion reacts with a primary alkyl halide. Which of the
following is the correct mechanism for this reaction?
A) SN1
B) SN2
C) E1
D) E2
Correct Answer: SN2
Rationale: The Williamson ether synthesis involves the reaction of an alkoxide ion (a strong
nucleophile) with a primary alkyl halide. The reaction proceeds via an SN2 mechanism because
primary alkyl halides are excellent substrates for SN2, and the alkoxide is a strong nucleophile.
Secondary and tertiary alkyl halides are avoided due to competing elimination.
Organic Chemistry w/Lab | Portage (2026–2027)
1. What is the correct IUPAC name for the compound shown below?
CH₃-CH₂-CH(OH)-CH₂-CH₂-CH₃
A) 3-hexanol
B) 2-hexanol
C) 4-hexanol
D) Hexan-3-ol
Correct Answer: 3-hexanol
Rationale: The longest carbon chain contains six carbons (hexane). The hydroxyl (-OH) group is the
principal functional group, taking the suffix "-ol". Numbering the chain from the end closest to the -
OH gives the hydroxyl group at carbon 3. Therefore, the correct IUPAC name is 3-hexanol. The other
options represent incorrect locants or names.
2. Which of the following alcohols is classified as a secondary alcohol?
A) 2-methyl-2-propanol
B) 2-butanol
C) 1-propanol
D) Cyclohexanol
Correct Answer: 2-butanol
Rationale: A secondary alcohol has the hydroxyl-bearing carbon bonded to two other carbon atoms.
In 2-butanol (CH₃-CH(OH)-CH₂-CH₃), carbon 2 is bonded to two carbon groups (a methyl and an ethyl),
making it secondary. 2-methyl-2-propanol and cyclohexanol are tertiary, and 1-propanol is primary.
3. Which of the following correctly explains why alcohols have higher boiling points than alkanes of
similar molecular weight?
,A) Alcohols have stronger London dispersion forces.
B) Alcohols can form hydrogen bonds with each other.
C) Alcohols are more polarizable than alkanes.
D) Alcohols have higher molecular weights.
Correct Answer: Alcohols can form hydrogen bonds with each other.
Rationale: Alcohols contain an O-H bond, allowing them to form intermolecular hydrogen bonds,
which are strong dipole-dipole interactions. These hydrogen bonds require significant energy to
overcome, leading to higher boiling points. Alkanes only exhibit weak London dispersion forces,
resulting in much lower boiling points.
4. What is the product of the acid-catalyzed dehydration of 2-butanol?
A) 1-butene
B) 2-butene
C) Butane
D) 2-butanone
Correct Answer: 2-butene
Rationale: Acid-catalyzed dehydration of an alcohol follows Zaitsev's rule, where the more substituted
alkene is the major product. Dehydration of 2-butanol (CH₃-CH(OH)-CH₂-CH₃) gives 2-butene (CH₃-
CH=CH-CH₃) as the major product, with 1-butene as a minor product. The reaction proceeds through a
carbocation intermediate.
5. Which of the following reagents would be used to convert a primary alcohol to an aldehyde?
A) KMnO₄ (hot, concentrated)
B) K₂Cr₂O₇ (Jones reagent)
C) PCC (pyridinium chlorochromate)
D) H₂SO₄ (concentrated)
, Correct Answer: PCC (pyridinium chlorochromate)
Rationale: PCC is a mild oxidizing agent that selectively oxidizes primary alcohols to aldehydes.
Stronger oxidizing agents like KMnO₄ or Jones reagent (K₂Cr₂O₇/H₂SO₄) will further oxidize the
aldehyde to a carboxylic acid. PCC stops at the aldehyde stage and is therefore the reagent of choice
for this transformation.
6. Which of the following is the correct structure for 3-methyl-2-butanol?
A) CH₃-CH(OH)-CH(CH₃)-CH₃
B) CH₃-CH(CH₃)-CH(OH)-CH₃
C) (CH₃)₂CH-CH₂-CH₂OH
D) CH₃-CH(OH)-CH₂-CH₂-CH₃
Correct Answer: CH₃-CH(OH)-CH(CH₃)-CH₃
Rationale: The parent chain is butanol (four carbons). A methyl group is attached to carbon 3, and the
hydroxyl group is on carbon 2. Numbering from the end closest to the -OH gives the lowest locant for
the hydroxyl. The structure CH₃-CH(OH)-CH(CH₃)-CH₃ matches this description.
7. In the Williamson ether synthesis, an alkoxide ion reacts with a primary alkyl halide. Which of the
following is the correct mechanism for this reaction?
A) SN1
B) SN2
C) E1
D) E2
Correct Answer: SN2
Rationale: The Williamson ether synthesis involves the reaction of an alkoxide ion (a strong
nucleophile) with a primary alkyl halide. The reaction proceeds via an SN2 mechanism because
primary alkyl halides are excellent substrates for SN2, and the alkoxide is a strong nucleophile.
Secondary and tertiary alkyl halides are avoided due to competing elimination.
