Question 1

Place asterisks at all the chirality centers in each molecule below. -Rank the following substituent groups from highest to lowest priority according to the sequencing rules. CO₂CH₃ CO₂H OH Cl

Accepted Answer

Cl > OH > CO₂CH₃ > CO₂H

Question 2

(−)-cholesterol

Accepted Answer

Cholesterol is a chiral molecule and its prefix (−)- indicates that it rotates the plane of polarized light counterclockwise, which is also known as being levorotatory.

Question 3

Identify the indicated hydrogens in the following molecules as pro-R or pro-S.
-Identify:  phenylpyruvate

Accepted Answer

phenylpyruvate

Question 4

Place asterisks at all the chirality centers in each molecule below.
-Place asterisks:  cephalexin

Accepted Answer

The answer of Place asterisks at all the chirality centers...

Question 5

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

Accepted Answer

Enantiomers are stereoisomers that are non-superimposable mirror images of one another. Choice A describes a pair of identical structures, while choice C describes diastereomers. Choice D is not a defining characteristic of enantiomers as it is possible for two enantiomers to have different specific rotations.

Question 6

Consider the structure of streptimidone below to answer the following question(s).  streptimidone
-Refer to instructions. Does streptimidone have a meso stereoisomer? Explain.

Accepted Answer

The answer of Consider the structure of streptimidone below to...

Question 7

The biological importance of enantiomers arises from?

Accepted Answer

All of these statements are true. Biological receptors are often chiral and require a specific enantiomer for a reaction to take place. Each enantiomer can have different biological properties and can affect biological processes differently. Therefore, the biological importance of enantiomers arises from a combination of factors.

Question 8

In the molecules below, assign R, S configurations to the chirality center indicated with an arrow.   norepinephrine
alanine
-Refer to instructions. The configuration of this carbon atom is _____.

Accepted Answer

The answer of In the molecules below, assign R, S...

Question 9

If (+)-sucrose has a specific rotation of +66.47, what is the specific rotation of (−)-sucrose?

Accepted Answer

The specific rotation of the enantiomer (mirror image) of a chiral molecule, such as sucrose, is equal in magnitude but opposite in sign to that of the original molecule. Therefore, if (+)-sucrose has a specific rotation of +66.47, then (−)-sucrose would have a specific rotation of −66.47.

Question 10

2.10 g of an unknown compound was dissolved in 15.00 mL of ethanol. The sample was placed in a 10.0 cm cell in a polarimeter and the angle of rotation was determined to be −18.48°. What is the specific rotation of this unknown and specify if the compound is levorotatory or dextrorotatory?

Accepted Answer

The answer of 2.10 g of an unknown compound was...

Question 11

In the molecules below, assign R, S configurations to the chirality center indicated with an arrow.   norepinephrine
alanine
-Refer to instructions. The configuration of this carbon atom is _____.

Accepted Answer

The answer of In the molecules below, assign R, S...

Question 12

Place asterisks at all the chirality centers in each molecule below.
-The following atoms are commonly encountered in organic molecules. For which is it not possible to isolate enantiomers due to rapid inversion?

Accepted Answer

Trivalent nitrogen cannot have stable enantiomers due to rapid inversion, which is often referred to as nitrogen inversion.

Question 13

Identify the indicated hydrogens in the following molecules as pro-R or pro-S.
-Identify:  succinate

Accepted Answer

The answer of Identify the indicated hydrogens in the following...

Question 14

Place asterisks at all the chirality centers in each molecule below.
-The numbers on the carbon center of the following molecule represent atomic numbers.  The molecule is in

Accepted Answer

The answer of Place asterisks at all the chirality centers...

Question 15

Which of the following physical properties can be used to identify a compound?

Accepted Answer

[α]_D (specific rotation) can be used to identify a compound, as it depends on the compound's molecular structure and stereochemistry. The other options (R, S, α) are not specific enough to identify a compound on their own.

Question 16

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

Accepted Answer

Diastereomers are a type of stereoisomers that are not mirror images of each other. This distinguishes them from enantiomers, which are non-superimposable mirror images.

Question 17

Which of the following has a plane of symmetry?

Accepted Answer

The laboratory beaker has a plane of symmetry down the middle, making it symmetrical on both sides. The hammer also has a plane of symmetry down the middle, making it symmetrical on both sides. The boot does not have a plane of symmetry since the left and right sides are not identical.

Question 18

Place asterisks at all the chirality centers in each molecule below.
-Place asterisks:  ephedrine

Accepted Answer

The answer of Place asterisks at all the chirality centers...

Question 19

Consider the structure of streptimidone below to answer the following question(s).  streptimidone
-Refer to instructions. Assign R or S configuration to each chirality center indicated in streptimidone.

Accepted Answer

The answer of Consider the structure of streptimidone below to...

Question 20

Place asterisks at all the chirality centers in each molecule below.
-Place asterisks:  codeine

Accepted Answer

The answer of Place asterisks at all the chirality centers...

Quiz 5: Stereochemistry at Tetrahedral Centers

Place asterisks at all the chirality centers in each molecule below. -Rank the following substituent groups from highest to lowest priority according to the sequencing rules. CO₂CH₃ CO₂H OH Cl

(−) -cholesterol

Identify the indicated hydrogens in the following molecules as pro-R or pro-S. -Identify: phenylpyruvate

Place asterisks at all the chirality centers in each molecule below. -Place asterisks: cephalexin

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

Consider the structure of streptimidone below to answer the following question(s). streptimidone -Refer to instructions. Does streptimidone have a meso stereoisomer? Explain.

The biological importance of enantiomers arises from?

In the molecules below, assign R, S configurations to the chirality center indicated with an arrow. norepinephrine alanine -Refer to instructions. The configuration of this carbon atom is _____.

If (+) -sucrose has a specific rotation of +66.47, what is the specific rotation of (−) -sucrose?

2.10 g of an unknown compound was dissolved in 15.00 mL of ethanol. The sample was placed in a 10.0 cm cell in a polarimeter and the angle of rotation was determined to be −18.48°. What is the specific rotation of this unknown and specify if the compound is levorotatory or dextrorotatory?

In the molecules below, assign R, S configurations to the chirality center indicated with an arrow. norepinephrine alanine -Refer to instructions. The configuration of this carbon atom is _____.

Place asterisks at all the chirality centers in each molecule below. -The following atoms are commonly encountered in organic molecules. For which is it not possible to isolate enantiomers due to rapid inversion?

Identify the indicated hydrogens in the following molecules as pro-R or pro-S. -Identify: succinate

Place asterisks at all the chirality centers in each molecule below. -The numbers on the carbon center of the following molecule represent atomic numbers. The molecule is in

Which of the following physical properties can be used to identify a compound?

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

Which of the following has a plane of symmetry?

Place asterisks at all the chirality centers in each molecule below. -Place asterisks: ephedrine

Consider the structure of streptimidone below to answer the following question(s). streptimidone -Refer to instructions. Assign R or S configuration to each chirality center indicated in streptimidone.

Place asterisks at all the chirality centers in each molecule below. -Place asterisks: codeine

Quiz 5: Stereochemistry at Tetrahedral Centers

Place asterisks at all the chirality centers in each molecule below. -Rank the following substituent groups from highest to lowest priority according to the sequencing rules. CO2CH3 CO2H OH Cl

(−) -cholesterol

Identify the indicated hydrogens in the following molecules as pro-R or pro-S. -Identify: phenylpyruvate

Place asterisks at all the chirality centers in each molecule below. -Place asterisks: cephalexin

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

Consider the structure of streptimidone below to answer the following question(s). streptimidone -Refer to instructions. Does streptimidone have a meso stereoisomer? Explain.

The biological importance of enantiomers arises from?

In the molecules below, assign R, S configurations to the chirality center indicated with an arrow. norepinephrine alanine -Refer to instructions. The configuration of this carbon atom is _____.

If (+) -sucrose has a specific rotation of +66.47, what is the specific rotation of (−) -sucrose?

2.10 g of an unknown compound was dissolved in 15.00 mL of ethanol. The sample was placed in a 10.0 cm cell in a polarimeter and the angle of rotation was determined to be −18.48°. What is the specific rotation of this unknown and specify if the compound is levorotatory or dextrorotatory?

In the molecules below, assign R, S configurations to the chirality center indicated with an arrow. norepinephrine alanine -Refer to instructions. The configuration of this carbon atom is _____.

Place asterisks at all the chirality centers in each molecule below. -The following atoms are commonly encountered in organic molecules. For which is it not possible to isolate enantiomers due to rapid inversion?

Identify the indicated hydrogens in the following molecules as pro-R or pro-S. -Identify: succinate

Place asterisks at all the chirality centers in each molecule below. -The numbers on the carbon center of the following molecule represent atomic numbers. The molecule is in

Which of the following physical properties can be used to identify a compound?

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

Which of the following has a plane of symmetry?

Place asterisks at all the chirality centers in each molecule below. -Place asterisks: ephedrine

Consider the structure of streptimidone below to answer the following question(s). streptimidone -Refer to instructions. Assign R or S configuration to each chirality center indicated in streptimidone.

Place asterisks at all the chirality centers in each molecule below. -Place asterisks: codeine

Place asterisks at all the chirality centers in each molecule below. -Rank the following substituent groups from highest to lowest priority according to the sequencing rules. CO₂CH₃ CO₂H OH Cl