Question 1

Instructions: Consider the structure of streptimidone below to answer the following question(s).

Refer to instructions. Assign R or S configuration to each chirality center indicated in streptimidone.

Accepted Answer

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Question 2

Which of the following has a plane of symmetry?&#10;A) boot&#10;B) laboratory beaker&#10;C) hammer&#10;D) both b and c&#10;E) none of these

Accepted Answer

A plane of symmetry refers to a hypothetical plane that divides an object into mirror-image halves. Both a laboratory beaker and a hammer have planes of symmetry. A beaker is usually symmetrical around its central axis, meaning if you cut it vertically down the middle, you'd get two identical halves. Similarly, a standard hammer can be divided into two mirror-image halves along its length, assuming it's a typical claw hammer with a symmetrical head and handle. A boot, on the other hand, does not have a plane of symmetry due to its irregular shape and the differentiation between the left and right foot.

Question 3

The biological importance of enantiomers arises from?&#10;A) Biological reactions involve receptor molecules.&#10;B) Biological receptors are chiral.&#10;C) Biological receptors require a specific enantiomer for reaction.&#10;D) Each enantiomer has different biological properties.&#10;E) all of these

Accepted Answer

Biological reactions involve receptor molecules, which are often chiral and require a specific enantiomer for reaction. Each enantiomer can have different biological properties, which can have significant impacts on the effectiveness and safety of drugs and other therapeutic agents. Therefore, the biological importance of enantiomers stems from all of these factors.

Question 4

Which of the following is the definition of a pair of enantiomers?&#10;A) A pair of structures that are superimposable mirror images of one another&#10;B) A pair of stereoisomers that are non-superimposable mirror images of one another&#10;C) A pair of stereoisomers that are not mirror images of one another&#10;D) A pair of stereoisomers that have equal specific rotations

Accepted Answer

Enantiomers are stereoisomers that are non-superimposable mirror images of each other. Option B correctly describes this definition. Option A describes a pair of identical structures. Option C describes diastereomers, which are stereoisomers that are not mirror images of each other. Option D describes meso compounds, which are a special type of stereoisomer that have a plane of symmetry and therefore have a specific rotation of zero.

Question 5

Which of the following physical properties can be used to identify a compound? A) R B) S C) a D) [a]_D

Accepted Answer

The specific rotation, denoted as [a]_D, is a physical property that can be used to identify chiral compounds by measuring the degree to which they rotate plane-polarized light.

Question 6

Instructions: Place asterisks at all the chirality centers in each molecule below.&#10;Place asterisks:&#10;

Accepted Answer

The answer of Instructions: Place asterisks at all the chirality...

Question 7

Instructions: In the molecules below, assign R, S configurations to the chirality center indicated with an arrow.

Refer to instructions. The configuration of the carbon atom labeled 19 is _____.

Accepted Answer

The answer of Instructions: In the molecules below, assign R,...

Question 8

Instructions: Place asterisks at all the chirality centers in each molecule below.&#10;Place asterisks:&#10;

Accepted Answer

The answer of Instructions: Place asterisks at all the chirality...

Question 9

Instructions: In the molecules below, assign R, S configurations to the chirality center indicated with an arrow.

Refer to instructions. The configuration of the carbon atom labeled 19 is _____.

Accepted Answer

The answer of Instructions: In the molecules below, assign R,...

Question 10

If (+)-sucrose has a specific rotation of +66.47, what is the specific rotation of (-)-sucrose?&#10;A) +66.47&#10;B) -66.47&#10;C) +33.43&#10;D) -33.43&#10;E) Must be determined with a polarimeter.

Accepted Answer

The specific rotation of a compound is dependent on the direction of polarized light rotation. The (+)-sucrose rotates polarized light to the right, so the (-)-sucrose would rotate polarized light to the left, giving a negative sign. Therefore, the answer is choice B.

Question 11

Which of the following is the definition of a pair of diastereomers?&#10;A) A pair of structures that are superimposable mirror images of one another&#10;B) A pair of stereoisomers that are non-superimposable mirror images of one another&#10;C) A pair of stereoisomers that are not mirror images of one another&#10;D) A pair of stereoisomers that have equal specific rotations

Accepted Answer

The answer of Which of the following is the definition...

Question 12

Rank the following substituent groups from highest to lowest priority according to the sequencing rules. CO₂CH₃ CO₂H OH Cl

Accepted Answer

The answer of Rank the following substituent groups from highest...

Question 13

Which of the following is the definition of a meso compound?&#10;A) A molecule with chirality centers which is chiral&#10;B) A molecule with chirality centers which is not chiral&#10;C) A diastereomer with no chirality centers&#10;D) A chiral compound with more than one chirality center

Accepted Answer

The answer of Which of the following is the definition...

Question 14

(-)-cholesterol&#10;A) does not have a chiral center.&#10;B) is dextrorotatory.&#10;C) rotates the plane of polarized light counterclockwise.&#10;D) does not rotate polarized light.

Accepted Answer

The answer of (-)-cholesterol&#10;A) does not have a chiral center.&#10;B)...

Question 15

Instructions: Place asterisks at all the chirality centers in each molecule below.&#10;Place asterisks:&#10;

Accepted Answer

The answer of Instructions: Place asterisks at all the chirality...

Question 16

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$\degree$. 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 17

The numbers on the carbon center of the following molecule represent atomic numbers.   The molecule is in&#10;A) the R configuration.&#10;B) the S configuration.&#10;C) The carbon is not a chiral center in this molecule.&#10;D) The exact configuration cannot be determined without knowing additional atomic numbers.

Accepted Answer

The answer of The numbers on the carbon center of...

Question 18

Instructions: Consider the structure of streptimidone below to answer the following question(s).&#10;   Refer to instructions. Does streptimidone have a meso stereoisomer? Explain.

Accepted Answer

The answer of Instructions: Consider the structure of streptimidone below...

Question 19

Which of the following statements is true regarding pairs of enantiomers?&#10;A) They have identical melting points&#10;B) They have identical boiling points.&#10;C) They rotate plane-polarized light in opposite directions&#10;D) They produce different products in reactions with chiral reagents&#10;E) all of these

Accepted Answer

The answer of Which of the following statements is true...

Question 20

Which of the following correctly describes a molecule that is achiral?&#10;A) Non-superimposability of the molecule on its mirror image&#10;B) Superimposability of the molecule on its mirror image&#10;C) Contains a carbon atom with four different substituents&#10;D) Does not have a plane of symmetry&#10;E) Both b and d

Accepted Answer

The answer of Which of the following correctly describes a...

Question 21

How many stereoisomers of 3-bromo-2-butanol exist?  &#10;A) 1&#10;B) 2&#10;C) 3&#10;D) 4

Accepted Answer

The answer of How many stereoisomers of 3-bromo-2-butanol exist? ...

Question 22

Which of the following have the R configuration?  &#10;A) only 1&#10;B) only 2&#10;C) only 1 and 2&#10;D) 1, 2 and 3

Accepted Answer

The answer of Which of the following have the R...

Question 23

Instructions:&#10;Refer to the structure below to answer the following questions.   Refer to instructions. Give the complete name of the enantiomer of (S)-(-)-serine.

Accepted Answer

The answer of Instructions:&#10;Refer to the structure below to answer...

Question 24

Which of the following compounds is (are) achiral?  &#10;A) only 1&#10;B) only 1 and 2&#10;C) only 2 and 3&#10;D) 1, 2 and 3

Accepted Answer

The answer of Which of the following compounds is (are)...

Question 25

What is the relationship between the following pair of structures?  &#10;A) They are enantiomers&#10;B) They are diastereomers&#10;C) The are constitutional isomers&#10;D) They are identical

Accepted Answer

The answer of What is the relationship between the following...

Question 26

Which of the following structures represent the same stereoisomer?  &#10;A) only 1 and 2&#10;B) only 1 and 3&#10;C) only 2 and 3&#10;D) 1, 2 and 3

Accepted Answer

The answer of Which of the following structures represent the...

Question 27

How many stereoisomers of 2,3-dimethylbutane exist?  &#10;A) 1&#10;B) 2&#10;C) 3&#10;D) 4

Accepted Answer

The answer of How many stereoisomers of 2,3-dimethylbutane exist? ...

Question 28

Which of the following structures contain a plane of symmetry?  &#10;A) 1&#10;B) 2&#10;C) 3&#10;D) All three contain a plane of symmetry

Accepted Answer

The answer of Which of the following structures contain a...

Question 29

How many stereoisomers of 3-chloro-2-methylbutane exist?  &#10;A) 1&#10;B) 2&#10;C) 3&#10;D) 4

Accepted Answer

The answer of How many stereoisomers of 3-chloro-2-methylbutane exist? ...

Question 30

What is the relationship between the following pair of structures?  &#10;A) They are enantiomers&#10;B) They are diastereomers&#10;C) The are constitutional isomers&#10;D) They are identical

Accepted Answer

The answer of What is the relationship between the following...

Question 31

Which of the following have the S configuration?  &#10;A) only 1&#10;B) only 2&#10;C) only 1 and 2&#10;D) 1, 2 and 3

Accepted Answer

The answer of Which of the following have the S...

Question 32

Instructions:&#10;Refer to the structure below to answer the following questions.   Refer to instructions. Draw the enantiomer of (S)-(-)-serine in a wedge-dash projection.

Accepted Answer

The answer of Instructions:&#10;Refer to the structure below to answer...

Question 33

A natural product having [a]_D = +40.3$\degree$ has been isolated and purified. This information indicates that the natural product: a. is racemic b. doanot rotate plene-polarized light c. is levaratetary. d. is dextarotatory.

Accepted Answer

The answer of A natural product having [a]_D = +40.3$\degree$...

Question 34

Match between columns&#10;                        Premises: Are stereoisomers that are not mirror images.&#10;Are stereoisomers that are not mirror images.&#10;Are stereoisomers that are not mirror images.&#10;Are stereoisomers that are not mirror images.&#10;Are stereoisomers that are not mirror images.&#10;Are stereoisomers that are not mirror images.&#10;Is an atom in a molecule that is bonded to four different atoms or groups of atoms.&#10;Is an atom in a molecule that is bonded to four different atoms or groups of atoms.&#10;Is an atom in a molecule that is bonded to four different atoms or groups of atoms.&#10;Is an atom in a molecule that is bonded to four different atoms or groups of atoms.&#10;Is an atom in a molecule that is bonded to four different atoms or groups of atoms.&#10;Is an atom in a molecule that is bonded to four different atoms or groups of atoms.&#10;Are designated either (&#177;) or d,l.&#10;Are designated either (&#177;) or d,l.&#10;Are designated either (&#177;) or d,l.&#10;Are designated either (&#177;) or d,l.&#10;Are designated either (&#177;) or d,l.&#10;Are designated either (&#177;) or d,l.&#10;Are molecules which contain both chirality centers and a plane of symmetry.&#10;Are molecules which contain both chirality centers and a plane of symmetry.&#10;Are molecules which contain both chirality centers and a plane of symmetry.&#10;Are molecules which contain both chirality centers and a plane of symmetry.&#10;Are molecules which contain both chirality centers and a plane of symmetry.&#10;Are molecules which contain both chirality centers and a plane of symmetry.&#10;Describes organic molecules which rotate plane-polarized light.&#10;Describes organic molecules which rotate plane-polarized light.&#10;Describes organic molecules which rotate plane-polarized light.&#10;Describes organic molecules which rotate plane-polarized light.&#10;Describes organic molecules which rotate plane-polarized light.&#10;Describes organic molecules which rotate plane-polarized light.&#10;Describes an sp3-hybridized atom that can become a chirality center by changing one of its attached groups.&#10;Describes an sp3-hybridized atom that can become a chirality center by changing one of its attached groups.&#10;Describes an sp3-hybridized atom that can become a chirality center by changing one of its attached groups.&#10;Describes an sp3-hybridized atom that can become a chirality center by changing one of its attached groups.&#10;Describes an sp3-hybridized atom that can become a chirality center by changing one of its attached groups.&#10;Describes an sp3-hybridized atom that can become a chirality center by changing one of its attached groups.

Accepted Answer

The Answer of enantiomers or optically active and racemates and is...

Deck 6: Sterechemistry at Tetrahedral Centers