Question 1

How many isomers (constitutional and stereoisomers) exist for dimethylcyclopentane?

Accepted Answer

A)  3 
B)  5 
C)  7 
D)  9 
A)  3 
B)  5 
C)  7 
D)  9

Question 2

In muscle tissue only (+)-lactic acid is found but in sour milk both (+)-lactic acid and (-)-lactic acid are present. This difference might be explained by the fact that the production of lactic acid in muscle tissue is catalyzed by biological catalysts or enzymes.

Accepted Answer

A) True 
 B)False

Question 3

Complete the following zig-zag structure so that it represents (2R,3R)-3-chlorobutan-2-ol.

Accepted Answer

The answer of Complete the following zig-zag structure so that...

Question 4

Which of the following Newman projections represents (2R,3R)-dibromobutane?

Accepted Answer

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

Question 5

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 6

Which of the following is the definition of chirality?

Accepted Answer

A)  The non-superposability of an object on its mirror image 
B)  The superposability of an object on its mirror image 
C)  A molecule that has a carbon atom with four different substituents 
D)  A molecule with a mirror image 
A)  The non-superposability of an object on its mirror image 
B)  The superposability of an object on its mirror image 
C)  A molecule that has a carbon atom with four different substituents 
D)  A molecule with a mirror image

Question 7

Which of the following is the definition of a pair of enantiomers?

Accepted Answer

A)  A pair of structures that are superposable mirror images of one another 
B)  A pair of stereoisomers that are non-superposable mirror images of one another 
C)  A pair of stereoisomers that are not mirror images of one another 
D)  A pair of stereoisomers that have equal specific rotations 
A)  A pair of structures that are superposable mirror images of one another 
B)  A pair of stereoisomers that are non-superposable mirror images of one another 
C)  A pair of stereoisomers that are not mirror images of one another 
D)  A pair of stereoisomers that have equal specific rotations

Question 8

Which of the following is the definition of a pair of diastereomers?

Accepted Answer

A)  A pair of structures that are superposable mirror images of one another 
B)  A pair of stereoisomers that are non-superposable mirror images of one another 
C)  A pair of stereoisomers that are not mirror images of one another 
D)  A pair of stereoisomers that have equal specific rotations 
A)  A pair of structures that are superposable mirror images of one another 
B)  A pair of stereoisomers that are non-superposable mirror images of one another 
C)  A pair of stereoisomers that are not mirror images of one another 
D)  A pair of stereoisomers that have equal specific rotations

Question 9

An unknown sample is tested with a polarimeter for optical activity. The results of the test required no movement of the analyzer. This sample could be either a meso compound or a racemic mixture.

Accepted Answer

A) True 
 B)False

Question 10

How many isomers (constitutional and stereoisomers) exist for dimethylpentane?

Accepted Answer

A)  2 
B)  3 
C)  4 
D)  5 
A)  2 
B)  3 
C)  4 
D)  5

Question 11

How many stereoisomers of 3-bromo-2-butanol, CH3CH(OH)CHBrCH3, exist?

Accepted Answer

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

Question 12

Which of the following structures is different from the other three?

Accepted Answer

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

Question 13

Complete the following diagram so that it represents (R)-2-bromobutane.

Accepted Answer

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

Question 14

How much of the R enantiomer is present in 10 g of a mixture which has an enantiomeric excess of 20% of the S isomer?

Accepted Answer

A)  1 g 
B)  2 g 
C)  4 g 
D)  6 g 
A)  1 g 
B)  2 g 
C)  4 g 
D)  6 g

Question 15

Complete the following zig-zag structure so that it represents (2S,3R)-2,3-dibromobutane.

Accepted Answer

The answer of Complete the following zig-zag structure so that...

Question 16

Which of the following structures is chiral?

Accepted Answer

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

Question 17

Complete the following diagram so that it represents (R)-2-bromobutane.

Accepted Answer

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

Question 18

Which of the following Newman projections represents meso-2,3-dibromobutane?

Accepted Answer

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

Question 19

The terms that best describe the relationship between (2R,3S)-2,3-butanediol and (2S,3S)-2,3-butanediol are configurational and diastereomers.

Accepted Answer

A) True 
 B)False

Question 20

Which of the following structures has a center of symmetry (i.e., center of inversion)?

Accepted Answer

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

Exam 3: Stereoisomerism and Chirality

How many isomers (constitutional and stereoisomers) exist for dimethylcyclopentane?

In muscle tissue only (+)-lactic acid is found but in sour milk both (+)-lactic acid and (-)-lactic acid are present. This difference might be explained by the fact that the production of lactic acid in muscle tissue is catalyzed by biological catalysts or enzymes.

Complete the following zig-zag structure so that it represents (2R,3R)-3-chlorobutan-2-ol.

Which of the following Newman projections represents (2R,3R)-dibromobutane?

What is the relationship between the following pair of structures?

Which of the following is the definition of chirality?

Which of the following is the definition of a pair of enantiomers?

Which of the following is the definition of a pair of diastereomers?

An unknown sample is tested with a polarimeter for optical activity. The results of the test required no movement of the analyzer. This sample could be either a meso compound or a racemic mixture.

How many isomers (constitutional and stereoisomers) exist for dimethylpentane?

How many stereoisomers of 3-bromo-2-butanol, CH3CH(OH)CHBrCH3, exist?

Which of the following structures is different from the other three?

Complete the following diagram so that it represents (R)-2-bromobutane.

How much of the R enantiomer is present in 10 g of a mixture which has an enantiomeric excess of 20% of the S isomer?

Complete the following zig-zag structure so that it represents (2S,3R)-2,3-dibromobutane.

Which of the following structures is chiral?

Complete the following diagram so that it represents (R)-2-bromobutane.

Which of the following Newman projections represents meso-2,3-dibromobutane?

The terms that best describe the relationship between (2R,3S)-2,3-butanediol and (2S,3S)-2,3-butanediol are configurational and diastereomers.

Which of the following structures has a center of symmetry (i.e., center of inversion)?

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

How many stereoisomers of 3-bromo-2-butanol, CH₃CH(OH)CHBrCH₃, exist?