Question 1

A natural product having [α]D = +40.3° has been isolated and purified. Either of the following substances could be this natural product.

Accepted Answer

A) True 
 B)False  False

Question 2

Which of the following compounds is a meso compound?

Accepted Answer

A)  (2R,3R)-dibromobutane 
B)  (2R,3S)-dibromobutane 
C)  (2R,3S)-3-bromo-2-butanol 
D)  (2R,3R)-3-bromo-2-butanol 
A)  (2R,3R)-dibromobutane 
B)  (2R,3S)-dibromobutane 
C)  (2R,3S)-3-bromo-2-butanol 
D)  (2R,3R)-3-bromo-2-butanol B

Question 3

A work glove is chiral but disposable surgical gloves are not.

Accepted Answer

A) True 
 B)False  True

Question 4

A natural product having [α]D = +40.3° has been isolated and purified. This indicates that the natural product is dextrorotatory.

Accepted Answer

A) True 
 B)False

Question 5

The specific rotation of the S-enantiomer of a compound is -120º. A student determines that a sample of the compound has a specific rotation of +60º. What mass of the S-enantiomer is present in 10 g of the sample

Accepted Answer

The answer of The specific rotation of the S-enantiomer of...

Question 6

How can enantiomers be separated using chromatography?

Accepted Answer

Enantiomers can be separated using chrom

Question 7

A solution containing 0.2 g/mL of a pure R enantiomer in a 1 dm polarimeter rotates plane polarized light by +3°. What is the specific rotation of the R isomer?

Accepted Answer

A)  +0.6° 
B)  +15° 
C)  +67° 
D)  +150° 
A)  +0.6° 
B)  +15° 
C)  +67° 
D)  +150°

Question 8

What is the relationship between the following pair of structures?

Accepted Answer

A)  They are enantiomers 
B)  They are diastereomers 
C)  The are constitutional isomers 
D)  They are identical 
A)  They are enantiomers 
B)  They are diastereomers 
C)  The are constitutional isomers 
D)  They are identical

Question 9

How many stereoisomers of 4-chloro-2-methylpentane (CH3)2CHCH2CHClCH3, exist?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
A)  1 
B)  2 
C)  3 
D)  4

Question 10

Complete the following Fischer diagram so that it represents (2R,3S)-3-bromobutan-2-ol.

Accepted Answer

The answer of Complete the following Fischer diagram so that...

Question 11

How many chiral centers are there in the following molecule (the naturally occurring stereoisomer is camphor, a pungent moth repellent)?

Accepted Answer

A)  Two 
B)  Three 
C)  Four 
D)  Five 
A)  Two 
B)  Three 
C)  Four 
D)  Five

Question 12

Complete the following Fischer diagram so that it represents (2R,3S)-butane-2,3-diol.

Accepted Answer

The answer of Complete the following Fischer diagram so that...

Question 13

Which of the following statements is not true regarding pairs of enantiomers?

Accepted Answer

A)  They have identical melting points 
B)  They have identical boiling points. 
C)  They rotate plane polarized light in opposite directions 
D)  They react at identical rates with chiral reagents 
A)  They have identical melting points 
B)  They have identical boiling points. 
C)  They rotate plane polarized light in opposite directions 
D)  They react at identical rates with chiral reagents

Question 14

Complete the following Fischer diagram so that it represents (2R,3R)-3-bromobutan-2-ol.

Accepted Answer

The answer of Complete the following Fischer diagram so that...

Question 15

Which of the following substituents has the highest priority according to the Cahn-Ingold-Prelog system used in assigning R and S configurations?

Accepted Answer

A)  −NH2 
B)  −NHCH3 
C)  −CH2NH2 
D)  −CH2NHCH3 
A)  −NH2 
B)  −NHCH3 
C)  −CH2NH2 
D)  −CH2NHCH3

Question 16

Of the following molecules, both 1 and 2 have a mirror plane of symmetry.

Accepted Answer

A) True 
 B)False

Question 17

Which of the following have the R configuration?

Accepted Answer

A)  only 1 
B)  only 2 
C)  only 1 and 2 
D)  1, 2 and 3 
A)  only 1 
B)  only 2 
C)  only 1 and 2 
D)  1, 2 and 3

Question 18

A solution containing 0.2 g/mL of a pure R enantiomer in a 1 dm polarimeter rotates plane polarized light by +2.8°. What is the rotation of a solution containing 0.4 g/mL of the R isomer in the same polarimeter?

Accepted Answer

A)  +0.7° 
B)  +1.4° 
C)  +2.8° 
D)  +5.6° 
A)  +0.7° 
B)  +1.4° 
C)  +2.8° 
D)  +5.6°

Question 19

Complete the following Newman projection so that it represents (2R,3R)-2,3-dibromobutane.

Accepted Answer

The answer of Complete the following Newman projection so that...

Question 20

Which of the following is the best definition of a pair of atropisomers?

Accepted Answer

A)  A pair of enantiomers which do not interconvert. 
B)  A pair of enantiomers which lack chiral centers. 
C)  A pair of enantiomeric structures which lack chiral centers and interconvert by rotation around carbon-carbon single bonds. 
D)  A pair of enantiomers which lack chiral centers and do not interconvert because of hindered rotation around carbon-carbon single bonds. 
A)  A pair of enantiomers which do not interconvert. 
B)  A pair of enantiomers which lack chiral centers. 
C)  A pair of enantiomeric structures which lack chiral centers and interconvert by rotation around carbon-carbon single bonds. 
D)  A pair of enantiomers which lack chiral centers and do not interconvert because of hindered rotation around carbon-carbon single bonds.

Exam 3: Stereoisomerism and Chirality

A natural product having [α]D = +40.3° has been isolated and purified. Either of the following substances could be this natural product.

Which of the following compounds is a meso compound?

A work glove is chiral but disposable surgical gloves are not.

A natural product having [α]D = +40.3° has been isolated and purified. This indicates that the natural product is dextrorotatory.

The specific rotation of the S-enantiomer of a compound is -120º. A student determines that a sample of the compound has a specific rotation of +60º. What mass of the S-enantiomer is present in 10 g of the sample

How can enantiomers be separated using chromatography?

A solution containing 0.2 g/mL of a pure R enantiomer in a 1 dm polarimeter rotates plane polarized light by +3°. What is the specific rotation of the R isomer?

What is the relationship between the following pair of structures?

How many stereoisomers of 4-chloro-2-methylpentane (CH3)2CHCH2CHClCH3, exist?

Complete the following Fischer diagram so that it represents (2R,3S)-3-bromobutan-2-ol.

How many chiral centers are there in the following molecule (the naturally occurring stereoisomer is camphor, a pungent moth repellent)?

Complete the following Fischer diagram so that it represents (2R,3S)-butane-2,3-diol.

Which of the following statements is not true regarding pairs of enantiomers?

Complete the following Fischer diagram so that it represents (2R,3R)-3-bromobutan-2-ol.

Which of the following substituents has the highest priority according to the Cahn-Ingold-Prelog system used in assigning R and S configurations?

Of the following molecules, both 1 and 2 have a mirror plane of symmetry.

Which of the following have the R configuration?

A solution containing 0.2 g/mL of a pure R enantiomer in a 1 dm polarimeter rotates plane polarized light by +2.8°. What is the rotation of a solution containing 0.4 g/mL of the R isomer in the same polarimeter?

Complete the following Newman projection so that it represents (2R,3R)-2,3-dibromobutane.

Which of the following is the best definition of a pair of atropisomers?

Covalent Bonding and Shapes of Molecules

Alkanes and Cycloalkanes

Acids and Bases

Alkenes: Bonding, Nomenclature, and Properties

Reactions of Alkenes

Alkynes

Haloalkanes, Halogenation, and Radical Reactions

Nucleophilic Substitution and Beta-Elimination

Alcohols

Ethers, Epoxides, and Sulfides

Infrared Spectroscopy

Nuclear Magnetic Resonance Spectroscopy

Mass Spectrometry

An Introduction to Organometallic Compounds

Aldehydes and Ketones

Carboxylic Acids

Functional Derivatives of Carboxylic Acids

Enolate Anions and Enamines

Dienes, Conjugated Systems, and Pericyclic Reactions

Benzene and the Concept of Aromaticity

Reactions of Benzene and Its Derivatives

Amines

Catalytic Carbon-Carbon Bond Formation

Carbohydrates

Lipids

Amino Acids and Proteins

Nucleic Acids

Organic Polymer Chemistry

Filters

A natural product having [α]_D = +40.3° has been isolated and purified. Either of the following substances could be this natural product.

A natural product having [α]_D = +40.3° has been isolated and purified. This indicates that the natural product is dextrorotatory.

How many stereoisomers of 4-chloro-2-methylpentane (CH₃)₂CHCH₂CHClCH₃, exist?