Deck 4: Isomers: the Arrangement of Atoms in Space

Question 1

Which of the following compounds have an asymmetric center?

A)
B)
C)
D)
E)

Answer 1

Question 2

How many asymmetric centers does the following compound have?

A) 2
B) 3
C) 1
D) 5
E) 4

Answer 2

1

Question 3

What is the relationship between the following compounds?

A) configurational isomers
B) conformational isomers
C) constitutional isomers
D) structural isomers
E) positional isomers

Answer 3

configurational isomers

Question 4

Which of the following compounds has an R configuration?

A)
B)
C)
D)

Question 5

Identify enantiomers.

A) B and D, A and C
B) A and C
C) B and D
D) A and B, A and D, B and C, C and D
E) B and D, A and B, A and D, B and C, C and D

Question 6

Which of the following is the enantiomer of the compound shown below?

A)
B)
C)
D)
E)

Question 7

What is the relationship between the following compounds?

A) identical compounds
B) conformational isomers
C) constitutional isomers
D) configurational isomers
E) enantiomers

Question 8

Which compounds have an asymmetric center?

A) A
B) B
C) C
D) A and B
E) A, B, and C

Question 9

What is the relative priority of the CH₃ group in the following compound?

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

Question 10

Which of the following compounds are not chiral?

A) 2,3 -dibromobutane
B) 1,3 -dibromobutane
C) 1,2 -dichlorobutane
D) 1,4-dibromobutane
E) 1-bromo-2-chlorobutane

Question 11

Which of the following groups has the highest priority?

A)
B)
C)
D)
E)

Question 12

What is the relationship between the following compounds?

A) identical compounds
B) constitutional isomers
C) conformational isomers
D) configurational isomers
E) enantiomers

Question 13

Identify identical compounds.

A) B and D, A and C
B) A and C
C) B and D
D) A and B, A and D, B and C, C and D
E) B and D, A and B, A and D, B and C, C and D

Question 14

How many asymmetric centers does the following compound have?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 15

What type of isomers are CH₃CH₂OCH₃ and CH₃CH₂CH₂OH?

A) constitutional
B) symmetrical
C) configurational
D) conformational
E) stereochemical

Question 16

Which of the following compounds has an asymmetric center? I.

II.

III.

IV.

V.

A) I
B) II
C) III
D) IV
E) V

Question 17

Which of the following compounds has an S configuration?

A)
B)
C)
D)

Question 18

What is the relative priority of the OH group in the following compound?

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

Question 19

How many asymmetric centers does 2,4,6-trimethylheptane have?

A) 0
B) 1
C) 2
D) 3
E) 4

Question 20

What is the relationship between the following compounds?

A) diastereomers
B) constitutional isomers
C) conformational isomers
D) configurational isomers
E) enantiomers

Question 21

A and B are stereoisomers. They are nonsuperimposable and are mirror images of one another. Which of the following best describes their relationship?

A) structural isomers
B) enantiomers
C) conformational isomers
D) diastereomers
E) constitutional isomers

Question 22

What is the relationship between the compounds shown below?

A) identical
B) conformational isomers
C) constitutional isomers
D) stereoisomers
E) none of the above

Question 23

How many stereoisomers does the following compound have? $$\mathrm { BrCH } _ { 2 } \mathrm { CH } \left( \mathrm { CH } _ { 3 } \right) \mathrm { CH } _ { 2 } \mathrm { CH } _ { 3 }$$

A) 0
B) 1
C) 2
D) 4
E) 8

Question 24

Which of the following are meso compounds?

A) trans-1,4-dimethylcyclohexane
B) cis-1,3-dimethylcyclohexane
C) trans-1,3-dimethylcyclohexane
D) cis-1,4-dimethylcyclohexane
E) trans-1,2-dimethylcyclohexane

Question 25

If (S)-glyceraldehyde has a specific rotation of -8.7, what is the specific rotation of (R)- glyceraldehyde?

A) -8.7
B) +8.7
C) 0.0
D) cannot be determined from the information given

Question 26

Which of the following statements describes an achiral molecule?

A) The molecule has a nonsuperimposable mirror image.
B) The molecule exhibits optical activity when it interacts with plane-polarized light.
C) The molecule has an enantiomer.
D) The molecule might be a meso compound.
E) None of the above

Question 27

Which of the following statements describes a pair of enantiomers?

A) They rotate the plane of polarized light by exactly the same amount and in opposite directions.
B) They rotate the plane of polarized light by differing amounts and in opposite directions.
C) They rotate the plane of polarized light by differing amounts and in the same direction.
D) They have different melting points.
E) They have the same melting point, but they have different boiling points.

Question 28

How many stereoisomers does the following compound have? $$\mathrm { CH } _ { 3 } \mathrm { CHClCH } _ { 2 } \mathrm { CHClCH } _ { 3 }$$

A) 0
B) 1
C) 2
D) 3
E) 4

Question 29

What is the relationship between the following compounds?

A) enantiomers
B) diastereomers
C) constitutional isomers
D) conformational isomers
E) identical compounds

Question 30

What is the relative priority of the CF₃ group in the following compound?

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

Question 31

Identify pairs of diastereomers.

A) B and D, A and C
B) A and C
C) B and D
D) A and B, A and D, B and C, C and D
E) B and D, A and B, A and D, B and C, C and D

Question 32

Which of the following statements describes the compound shown below?

A) It is achiral.
B) It is meso.
C) Its asymmetric center possesses the R configuration.
D) The mirror image of this molecule is its enantiomer.

Question 33

A mixture of equal amounts of two enantiomers ________.

A) is called a racemic mixture
B) is optically inactive
C) implies that the enantiomers are meso forms
D) both A and B
E) none of the above

Question 34

Which of the following are chiral?

A) cis-1-bromo-3-chlorocyclobutane
B) trans-1-bromo-3-chlorocyclobutane
C) cis-1,4-dimethylcyclohexane
D) cis-1,3-dimethylcyclohexane
E) trans-1,3-dimethylcyclohexane

Question 35

What is the relationship between the compounds shown below?

A) enantiomers
B) configurational isomers
C) conformational isomers
D) identical compounds
E) constitutional isomers

Question 36

Which of the following is a true statement?

A) All chiral molecules possess a plane of symmetry.
B) All achiral molecules are meso compounds.
C) All molecules that possess an asymmetric center with the S configuration are levorotatory.
D) A mixture of achiral compounds is optically inactive.
E) All molecules that possess two or more chirality centers are chiral.

Question 37

Which of the following is not true about enantiomers?

A) They have the same melting point.
B) They have the same boiling point.
C) They have the same chemical reactivity with non-chiral reagents.
D) They have the same density.
E) They have the same specific rotation.

Question 38

The specific rotation of a pure substance is 1.68. What is the specific rotation of a mixture containing 75% of this isomer and 25% of the (-) isomer?

A) +1.68
B) 0
C) +1.26
D) +0.84
E) +.042

Question 39

What is the relationship between the following compounds?

A) enantiomers
B) diastereomers
C) constitutional isomers
D) conformational isomers
E) identical compounds

Question 40

Which of the following are optically inactive?

A) a 50-50 mixture of R and S enantiomers
B) a meso compound
C) every achiral compound
D) a racemic mixture
E) all the above

Question 41

The compound contains only one asymmetric center. Explain why it has four stereoisomers.

Question 42

Which of the following terms describes the pair of compounds shown below: enantiomers,
diastereomers, or the same compound?

Question 43

Which of the following terms describes the pair of compounds shown below: enantiomers,
diastereomers, or the same compound?

Question 44

Which of the following terms describes the pair of compounds shown below: enantiomers,
diastereomers, or the same compound?

Question 45

Can you predict whether a compound with a single asymmetric center is based on the R/S assignment of the asymmetric center? Explain.

Question 46

Which of the following terms describes the pair of compounds shown below: enantiomers,
diastereomers, or the same compound?

Question 47

Draw (S)-1-bromo-1-chloropropane.

Question 48

Draw the enantiomer of the compound shown below.

Question 49

Draw the skeletal structure for (R)-4-octanol.

Question 50

Draw the stereoisomers of 1,2-dichlorocyclopentane.

Question 51

How many asymmetric centers does the following compound have?

Question 52

Is the compound shown below chiral or achiral?

Question 53

Is the compound shown below chiral or achiral?

Question 54

Which of the following compounds are not chiral?

Question 55

Which of the following terms describes the pair of compounds shown below: enantiomers,
diastereomers, or the same compound?

Question 56

Is the compound shown below chiral or achiral?

Question 57

Stereoisomers that are not mirror images are called ________.

Question 58

Is the compound shown below chiral or achiral?

Question 59

Draw the structure of the meso form of 1,3-dichlorocyclopentane.

Question 60

Does the asymmetric center in the following compound have the R or S configuration?

Question 61

Draw the structure of (Z)-4-ethyl-3,6-dimethyl-3-heptene.

Question 62

Is the compound shown below chiral or achiral?

Question 63

What is the configuration of the following compoound?

A) cis
B) E
C) trans
D) Z
E) none of the above

Question 64

What is the configuration of the following compoound?

A) cis
B) trans
C) E
D) Z
E) none of the above

Question 65

What is the configuration of the following compoound?

A) E
B) Z
C) neither E nor Z

Question 66

Is the compound shown below chiral or achiral?

Question 67

Is the compound shown below chiral or achiral? Is it a meso compound?

Question 68

Is the compound shown below chiral or achiral?

Question 69

Is the compound shown below chiral or achiral? Is it a meso compound?

Question 70

What is the configuration of the following compoound?

A) Z
B) trans
C) E
D) cis
E) none of the above

Question 71

Is the compound shown below chiral or achiral?

Question 72

Is the compound shown below chiral or achiral? Is it a meso compound?

Question 73

Which of the following compounds have cis-trans isomers?

A) 1-butene
B) 1-pentene
C) cyclohexene
D) ethene
E) 2-butene

Question 74

Name the following compound:

A) (2E,4E)-7-chloro-2,4-heptadiene
B) (2Z,4E)-7-chloro-2,4-heptadiene
C) (2Z,4Z)-7-chloro-2,4-heptadiene
D) (2E,4Z)-7-chloro-2,4-heptadiene
E) 7-chloro-2,4-heptadiene

Question 75

What is the configuration of the following compoound?

A) cis
B) trans
C) E
D) Z
E) none of the above

Question 76

Draw the structure of (Z)-4-ethyl-3-methylheptene.

Question 77

Does the following compound have the E or Z configuration?