CHEM 219 Principles of Organic Chemistry - Cumulative Final Exam
2026/2027 UPDATE
1. What is the hybridization of the carbon atom in methane (CH4)?
A. sp3
B. sp2
C. sp
D. sp3d
Answer: A
Rationale: Methane has four single bonds and no lone pairs on the central carbon atom,
resulting in a tetrahedral geometry and sp3 hybridization.
2. Which of the following describes the relationship between enantiomers?
A. Superimposable mirror images
B. Identical molecules with different rotations
C. Non-superimposable non-mirror images
D. Non-superimposable mirror images
Answer: D
Rationale: Enantiomers are a type of stereoisomer where the molecules are non-
superimposable mirror images of each other.
,3. In an SN2 reaction, what happens to the configuration of a chiral center?
A. Retention of configuration
B. Racemization
C. Inversion of configuration
D. No change in configuration
Answer: C
Rationale: SN2 reactions involve a backside attack by the nucleophile, leading to a
complete inversion of configuration at the chiral center, known as Walden inversion.
4. Which carbocation is the most stable?
A. Primary carbocation
B. Tertiary carbocation
C. Secondary carbocation
D. Methyl carbocation
Answer: B
Rationale: Stability increases with more alkyl groups attached to the positive carbon due
to inductive effects and hyperconjugation; thus, tertiary is the most stable.
5. What is the product of the reaction between an alkene and HBr in the
presence of peroxides?
A. Markovnikov addition product
B. Anti-Markovnikov addition product
C. Vicinal dibromide
D. Geminal dibromide
Answer: B
Rationale: Peroxides initiate a radical mechanism that leads to the bromine atom attaching
to the less substituted carbon, known as anti-Markovnikov addition.
, 6. What functional group is characterized by a carbon-oxygen double bond and
a hydroxyl group on the same carbon?
A. Aldehyde
B. Ketone
C. Ester
D. Carboxylic acid
Answer: D
Rationale: A carboxylic acid contains a carboxyl group, which consists of a carbonyl (C=O)
and a hydroxyl (O-H) group.
7. Which reagent is used for the syn-dihydroxylation of an alkene?
A. mCPBA followed by H3O+
B. OsO4 (Osmium tetroxide)
C. O3 (Ozone)
D. H2 with Pd/C
Answer: B
Rationale: Osmium tetroxide (OsO4) or cold, dilute KMnO4 are reagents used to add two
hydroxyl groups to the same side of an alkene (syn-addition).
8. In IR spectroscopy, where would you expect to see a strong, broad peak for
an O-H stretch?
A. 3200-3600 cm-1
B. 2200-2250 cm-1
C. 1700-1750 cm-1
D. 1600-1680 cm-1
Answer: A
Rationale: The O-H bond stretch typically appears as a very broad and strong peak in the
3200-3600 cm-1 region due to hydrogen bonding.
2026/2027 UPDATE
1. What is the hybridization of the carbon atom in methane (CH4)?
A. sp3
B. sp2
C. sp
D. sp3d
Answer: A
Rationale: Methane has four single bonds and no lone pairs on the central carbon atom,
resulting in a tetrahedral geometry and sp3 hybridization.
2. Which of the following describes the relationship between enantiomers?
A. Superimposable mirror images
B. Identical molecules with different rotations
C. Non-superimposable non-mirror images
D. Non-superimposable mirror images
Answer: D
Rationale: Enantiomers are a type of stereoisomer where the molecules are non-
superimposable mirror images of each other.
,3. In an SN2 reaction, what happens to the configuration of a chiral center?
A. Retention of configuration
B. Racemization
C. Inversion of configuration
D. No change in configuration
Answer: C
Rationale: SN2 reactions involve a backside attack by the nucleophile, leading to a
complete inversion of configuration at the chiral center, known as Walden inversion.
4. Which carbocation is the most stable?
A. Primary carbocation
B. Tertiary carbocation
C. Secondary carbocation
D. Methyl carbocation
Answer: B
Rationale: Stability increases with more alkyl groups attached to the positive carbon due
to inductive effects and hyperconjugation; thus, tertiary is the most stable.
5. What is the product of the reaction between an alkene and HBr in the
presence of peroxides?
A. Markovnikov addition product
B. Anti-Markovnikov addition product
C. Vicinal dibromide
D. Geminal dibromide
Answer: B
Rationale: Peroxides initiate a radical mechanism that leads to the bromine atom attaching
to the less substituted carbon, known as anti-Markovnikov addition.
, 6. What functional group is characterized by a carbon-oxygen double bond and
a hydroxyl group on the same carbon?
A. Aldehyde
B. Ketone
C. Ester
D. Carboxylic acid
Answer: D
Rationale: A carboxylic acid contains a carboxyl group, which consists of a carbonyl (C=O)
and a hydroxyl (O-H) group.
7. Which reagent is used for the syn-dihydroxylation of an alkene?
A. mCPBA followed by H3O+
B. OsO4 (Osmium tetroxide)
C. O3 (Ozone)
D. H2 with Pd/C
Answer: B
Rationale: Osmium tetroxide (OsO4) or cold, dilute KMnO4 are reagents used to add two
hydroxyl groups to the same side of an alkene (syn-addition).
8. In IR spectroscopy, where would you expect to see a strong, broad peak for
an O-H stretch?
A. 3200-3600 cm-1
B. 2200-2250 cm-1
C. 1700-1750 cm-1
D. 1600-1680 cm-1
Answer: A
Rationale: The O-H bond stretch typically appears as a very broad and strong peak in the
3200-3600 cm-1 region due to hydrogen bonding.
