Question 1

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 2

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 C

Question 3

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

Accepted Answer

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

Question 4

The specific rotation of the S-enantiomer of a compound is -120$\degree$. A student determines that a sample of the compound has a specific rotation of +60$\degree$. 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 5

How many stereoisomers of 2,4-dimethylpentane, (CH3)2CHCH2CH(CH3)2, exist?

Accepted Answer

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

Question 6

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

Accepted Answer

A)  +0.6$\degree$ 
B)  +15$\degree$ 
C)  +67$\degree$ 
D)  +150$\degree$ 
A)  +0.6$\degree$ 
B)  +15$\degree$ 
C)  +67$\degree$ 
D)  +150$\degree$

Question 7

What is the configuration of the two chiral centers in the following molecule?

Accepted Answer

A)  3R,5R 
B)  3R,5S 
C)  3S,5R 
D)  3S,5S 
A)  3R,5R 
B)  3R,5S 
C)  3S,5R 
D)  3S,5S

Question 8

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

Accepted Answer

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Question 9

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

Accepted Answer

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

Question 10

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 11

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)  -COOH 
B)  -CHO 
C)  -CH2OH 
D)  -CH3 
A)  -COOH 
B)  -CHO 
C)  -CH2OH 
D)  -CH3

Question 12

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 13

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 14

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

Accepted Answer

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

Question 15

Which of the following statements is true?

Accepted Answer

A)  All mirror images are enantiomers 
B)  All molecules that have stereocenter centers are chiral 
C)  Isomers that are not superposable on their mirror images are enantiomers 
D)  Superposable structural isomers are enantiomers 
A)  All mirror images are enantiomers 
B)  All molecules that have stereocenter centers are chiral 
C)  Isomers that are not superposable on their mirror images are enantiomers 
D)  Superposable structural isomers are enantiomers

Question 16

How many stereoisomers of 3-chloro-2-methylbutane, (CH3)2CHCHClCH3, exist?

Accepted Answer

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

Question 17

What is the correct order of the Cahn-Ingold-Prelog ranking of the following substituents as used in assigning R and S configurations of chiral centers? (higher ranking > lower ranking)

Accepted Answer

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

Question 18

Which of the following structures represent the same stereoisomer?

Accepted Answer

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

Question 19

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

Accepted Answer

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

Question 20

A pure sample of the R enantiomer of a compound has a specific rotation, [a], of -15$\degree$. A solution containing 0.6 g/mL of a mixture of enantiomers rotates plane polarized light by -3$\degree$ in a 1 dm polarimeter. What is the enantiomeric excess (%ee) of the mixture?

Accepted Answer

A)  33% R 
B)  33% S 
C)  50% R 
D)  75% R 
A)  33% R 
B)  33% S 
C)  50% R 
D)  75% R

Exam 3: Stereoisomerism and Chirality

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

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

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

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

How many stereoisomers of 2,4-dimethylpentane, (CH3)2CHCH2CH(CH3)2, exist?

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

What is the configuration of the two chiral centers in the following molecule?

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

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

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

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

Which of the following have the R configuration?

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 Newman projection so that it represents (2S,3S)-2,3-butanediol.

Which of the following statements is true?

How many stereoisomers of 3-chloro-2-methylbutane, (CH3)2CHCHClCH3, exist?

What is the correct order of the Cahn-Ingold-Prelog ranking of the following substituents as used in assigning R and S configurations of chiral centers? (higher ranking > lower ranking)

Which of the following structures represent the same stereoisomer?

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

A pure sample of the R enantiomer of a compound has a specific rotation, [a], of -15 °\degree° . A solution containing 0.6 g/mL of a mixture of enantiomers rotates plane polarized light by -3 °\degree° in a 1 dm polarimeter. What is the enantiomeric excess (%ee) of the mixture?

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

Filters

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

How many stereoisomers of 2,4-dimethylpentane, (CH₃)₂CHCH₂CH(CH₃)₂, exist?

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

How many stereoisomers of 3-chloro-2-methylbutane, (CH₃)₂CHCHClCH₃, exist?

A pure sample of the R enantiomer of a compound has a specific rotation, [a], of -15 $\degree$ . A solution containing 0.6 g/mL of a mixture of enantiomers rotates plane polarized light by -3 $\degree$ in a 1 dm polarimeter. What is the enantiomeric excess (%ee) of the mixture?