CHEM 219 PORTAGE LEARNING FINAL EXAM– QUESTIONS
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1. What is the hybridization of the central carbon atom in a methane molecule (CH4)?
A. sp
B. sp2
C. sp3
D. p3
Methane has four single sigma bonds surrounding the central carbon atom, resulting in
tetrahedral geometry and sp3 hybridization.
2. Which of the following functional groups contains a carbonyl group bonded to a
hydroxyl group?
A. Ketone
B. Aldehyde
C. Carboxylic acid
D. Ester
Carboxylic acids contain a carbonyl group (C=O) directly attached to a hydroxyl group (-OH),
whereas ketones have two carbon groups, aldehydes have a hydrogen, and esters have an
alkoxy group.
3. What is the IUPAC name for the straight-chain alkane containing five carbon atoms?
A. Butane
B. Pentane
C. Hexane
D. Heptane
,An alkane with five carbons is named pentane, following the standard IUPAC prefix 'pent-'
for five and '-ane' for single-bonded hydrocarbons.
4. Which type of isomerism is exhibited by cis-2-butene and trans-2-butene?
A. Constitutional isomerism
B. Enantiomerism
C. Conformational isomerism
D. Cis-trans (geometric) isomerism
Cis-2-butene and trans-2-butene are stereoisomers that differ in the spatial arrangement of
groups around a restricted rotation double bond, specifically geometric isomerism.
5. What is the primary driving force for an SN2 reaction mechanism?
A. Formation of a stable carbocation intermediate
B. Backside attack of a nucleophile on an electrophilic carbon with a good leaving group
C. Radical abstraction of a hydrogen atom
D. Elimination of a beta-hydrogen by a strong base
The SN2 mechanism proceeds via a concerted, single-step pathway involving a backside
nucleophilic attack, resulting in inversion of stereochemistry.
6. Which of the following compounds is classified as an aromatic hydrocarbon according to
Huckel's rule?
A. Cyclobutadiene
B. Benzene
C. Cyclooctatetraene
D. 1,3-Cyclopentadiene
Benzene is planar, fully conjugated, and contains 6 pi electrons, satisfying Huckel's rule (4n +
2 where n = 1), making it aromatic.
7. In an IR spectrum, a sharp, strong absorption peak around 1710 cm^-1 typically
indicates the presence of which functional group?
,A. O-H stretch of an alcohol
B. C=O stretch of a carbonyl group
C. C=C stretch of an alkene
D. C-H stretch of an alkane
The carbonyl group (C=O) characteristically absorbs infrared radiation strongly around
1680–1750 cm^-1 due to a large dipole moment change during vibration.
8. What is the major organic product formed when 2-butanol is treated with concentrated
sulfuric acid and heat?
A. 1-Butene
B. 2-Butene
C. Butane
D. 2-Butanol
Acid-catalyzed dehydration of 2-butanol proceeds via an E1 mechanism through a secondary
carbocation, yielding Zaitsev's rule-favored, more substituted 2-butene as the major product.
9. Which of the following alkyl halides undergoes solvolysis (SN1 reaction) most rapidly in
aqueous ethanol?
A. 1-Chlorobutane
B. 2-Chlorobutane
C. 2-Chloro-2-methylpropane
D. Chloromethane
Tertiary alkyl halides undergo SN1 reactions most rapidly because they form stable tertiary
carbocation intermediates during the rate-determining step.
10. What term describes stereoisomers that are non-superimposable mirror images of each
other?
A. Diastereomers
B. Enantiomers
, C. Constitutional isomers
D. Meso compounds
Enantiomers are chiral molecules that are exact non-superimposable mirror images,
possessing identical physical properties except for the direction of optical rotation.
11. Which reagent is commonly used to convert an alkene into a 1,2-diol (glycol) via syn-
addition?
A. OsO4 (Osmium tetroxide)
B. H2 / Pd-C
C. Br2 / CCl4
D. HCl / H2O
Osmium tetroxide reacts with alkenes to form a cyclic osmate ester intermediate, which
hydrolyzes to yield a 1,2-diol with syn stereochemistry.
12. What is the IUPAC name for the compound CH3CH(OH)CH2CH3?
A. 1-Butanol
B. 2-Butanol
C. 2-Butanone
D. Butanal
The longest carbon chain contains four carbons (butane) with the hydroxyl group located on
carbon 2, giving 2-butanol.
13. Which of the following represents a meso compound?
A. A chiral molecule with one stereocenter
B. A molecule with multiple stereocenters and an internal plane of symmetry, making it
optically inactive
C. A pair of enantiomers in equal proportions
D. A constitutional isomer of an alkane
AND ANSWERS | VERIFIED AND WELL DETAILED ANSWERS
PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM
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1. What is the hybridization of the central carbon atom in a methane molecule (CH4)?
A. sp
B. sp2
C. sp3
D. p3
Methane has four single sigma bonds surrounding the central carbon atom, resulting in
tetrahedral geometry and sp3 hybridization.
2. Which of the following functional groups contains a carbonyl group bonded to a
hydroxyl group?
A. Ketone
B. Aldehyde
C. Carboxylic acid
D. Ester
Carboxylic acids contain a carbonyl group (C=O) directly attached to a hydroxyl group (-OH),
whereas ketones have two carbon groups, aldehydes have a hydrogen, and esters have an
alkoxy group.
3. What is the IUPAC name for the straight-chain alkane containing five carbon atoms?
A. Butane
B. Pentane
C. Hexane
D. Heptane
,An alkane with five carbons is named pentane, following the standard IUPAC prefix 'pent-'
for five and '-ane' for single-bonded hydrocarbons.
4. Which type of isomerism is exhibited by cis-2-butene and trans-2-butene?
A. Constitutional isomerism
B. Enantiomerism
C. Conformational isomerism
D. Cis-trans (geometric) isomerism
Cis-2-butene and trans-2-butene are stereoisomers that differ in the spatial arrangement of
groups around a restricted rotation double bond, specifically geometric isomerism.
5. What is the primary driving force for an SN2 reaction mechanism?
A. Formation of a stable carbocation intermediate
B. Backside attack of a nucleophile on an electrophilic carbon with a good leaving group
C. Radical abstraction of a hydrogen atom
D. Elimination of a beta-hydrogen by a strong base
The SN2 mechanism proceeds via a concerted, single-step pathway involving a backside
nucleophilic attack, resulting in inversion of stereochemistry.
6. Which of the following compounds is classified as an aromatic hydrocarbon according to
Huckel's rule?
A. Cyclobutadiene
B. Benzene
C. Cyclooctatetraene
D. 1,3-Cyclopentadiene
Benzene is planar, fully conjugated, and contains 6 pi electrons, satisfying Huckel's rule (4n +
2 where n = 1), making it aromatic.
7. In an IR spectrum, a sharp, strong absorption peak around 1710 cm^-1 typically
indicates the presence of which functional group?
,A. O-H stretch of an alcohol
B. C=O stretch of a carbonyl group
C. C=C stretch of an alkene
D. C-H stretch of an alkane
The carbonyl group (C=O) characteristically absorbs infrared radiation strongly around
1680–1750 cm^-1 due to a large dipole moment change during vibration.
8. What is the major organic product formed when 2-butanol is treated with concentrated
sulfuric acid and heat?
A. 1-Butene
B. 2-Butene
C. Butane
D. 2-Butanol
Acid-catalyzed dehydration of 2-butanol proceeds via an E1 mechanism through a secondary
carbocation, yielding Zaitsev's rule-favored, more substituted 2-butene as the major product.
9. Which of the following alkyl halides undergoes solvolysis (SN1 reaction) most rapidly in
aqueous ethanol?
A. 1-Chlorobutane
B. 2-Chlorobutane
C. 2-Chloro-2-methylpropane
D. Chloromethane
Tertiary alkyl halides undergo SN1 reactions most rapidly because they form stable tertiary
carbocation intermediates during the rate-determining step.
10. What term describes stereoisomers that are non-superimposable mirror images of each
other?
A. Diastereomers
B. Enantiomers
, C. Constitutional isomers
D. Meso compounds
Enantiomers are chiral molecules that are exact non-superimposable mirror images,
possessing identical physical properties except for the direction of optical rotation.
11. Which reagent is commonly used to convert an alkene into a 1,2-diol (glycol) via syn-
addition?
A. OsO4 (Osmium tetroxide)
B. H2 / Pd-C
C. Br2 / CCl4
D. HCl / H2O
Osmium tetroxide reacts with alkenes to form a cyclic osmate ester intermediate, which
hydrolyzes to yield a 1,2-diol with syn stereochemistry.
12. What is the IUPAC name for the compound CH3CH(OH)CH2CH3?
A. 1-Butanol
B. 2-Butanol
C. 2-Butanone
D. Butanal
The longest carbon chain contains four carbons (butane) with the hydroxyl group located on
carbon 2, giving 2-butanol.
13. Which of the following represents a meso compound?
A. A chiral molecule with one stereocenter
B. A molecule with multiple stereocenters and an internal plane of symmetry, making it
optically inactive
C. A pair of enantiomers in equal proportions
D. A constitutional isomer of an alkane
