Ch5 Stereochemistry: Chiral Molecules Test Bank Answers

Package Title: Solomons Test Bank

Course Title: Solomons 13e

Chapter Number: 5

Question type: Multiple Choice

1) Cis-trans isomers are:

A) diastereomers.

B) enantiomers.

C) stereoisomers.

D) constitutional isomers.

E) More than one of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2

Difficulty: Easy

2) Enantiomers are:

A) molecules that have a mirror image.

B) molecules that have at least one stereogenic center.

C) non-superposable molecules.

D) non-superposable constitutional isomers.

E) non-superposable molecules that are mirror images of each other.

Topic: General definitions

Section Reference 1: 5.2

Difficulty: Easy

3) How many stereogenic centers are in the following compound:

A) 1

B) 3

C) 4

D) 5

E) none of these choices

Topic: General stereochemistry

Section Reference 1: 5.4

Difficulty: Medium

4) Which molecule is achiral?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.1, 5.4

Difficulty: Easy

5) Which molecule is achiral?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.1, 5.4

Difficulty: Easy

6) Which of the following compounds are chiral?

A) I, IV, and V

B) II only

C) II and III

D) III only

E) all compounds are achiral

Topic: Identifications and Comparisons

Section Reference 1: 5.1, 5.4

Difficulty: Medium

7) Pairs of enantiomers are:

A) I, II and III, IV

B) I, II

C) III, IV

D) IV, V

E) None of the structures.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4

Difficulty: Medium

8) Chiral molecules are represented by:

A) I, II, III, IV and V

B) I, II, III and IV

C) I and II

D) III and IV

E) IV alone

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4

Difficulty: Medium

9) What is the molecular formula for the alkane of smallest molecular weight which possesses a stereogenic center?

A) C₄H₁₀

B) C₅H₁₂

C) C₆H₁₄

D) C₇H₁₆

E) C₈H₁₈

Topic: General stereochemistry

Section Reference 1: 5.2A, 5.4

Difficulty: Medium

10) (R)-2-Chlorobutane is represented by:

A) I

B) II

C) III

D) IV

E) V

Topic: Specific names

Section Reference 1: 4.3, 5.7

Difficulty: Easy

11) Which of the following represent (R)-2-butanol?

A) III and V

B) I, III, IV and V

C) I, IV and V

D) I and III

E) I, II, IV and V

Topic: Specific names

Section Reference 1: 4.3, 5.7

Difficulty: Easy

12) Which structure represents (S)-1-chloro-1-fluoroethane?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Specific names

Section Reference 1: 4.3, 5.7

Difficulty: Easy

13) Which structure represents (R)-1-chloro-1-fluoroethane?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Specific names

Section Reference 1: 4.3, 5.7

Difficulty: Easy

14) What is IUPAC name of the following compound?

A) (R)-2-methyl-3-butyn-1-ol

B) (S)-2-methyl-3-butyn-1-ol

C) (R)-2-methyl-1-butyn-3-ol

D) (S)-2-methyl-1-butyn-3-ol

E) None of these choices

Topic: Specific Names

Section Reference 1: 4.3, 5.7

Difficulty: Medium

15) Which structure represents (S)-2-bromobutane?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Specific names

Section Reference 1: 4.3, 5.7

Difficulty: Easy

16) Which of the following is the enantiomer of the following substance?

A) I

B) II

C) III

D) It does not have a non-superposable enantiomer.

E) Both II and III.

Topic: Identifications and Comparisons

Section Reference 1: 5.3, 5.4, and 5.7

Difficulty: Easy

17) What is the total number of compounds, stereoisomers included, designated by the general name "dichlorocyclopentane"?

A) 4

B) 5

C) 7

D) 8

E) 9

Topic: General stereochemistry

Section Reference 1: 5.6, 5.7

Difficulty: Medium

18) Which of the following is NOT true of enantiomers? They have the same:

A) boiling point.

B) melting point.

C) specific rotation.

D) density.

E) chemical reactivity toward achiral reagents.

Topic: General definitions

Section Reference 1: 5.8

Difficulty: Easy

19) Which of these is a comparatively insignificant factor affecting the magnitude of specific optical rotation?

A) concentration of the substance of interest

B) purity of the sample

C) temperature of the measurement

D) length of the sample tube

E) All of these choices are equally significant.

Topic: Optical activity

Section Reference 1: 5.8

Difficulty: Medium

20) Which of the following is true about any (R)-enantiomer?

A) It is dextrorotatory.

B) It is levorotatory.

C) It is an equal mixture of + and –.

D) It is the mirror image of the (S)-enantiomer.

E) (R) indicates a racemic mixture.

Topic: General definitions

Section Reference 1: 5.3, 5.4, 5.8

Difficulty: Easy

21) Which of the following is true of any (S)-enantiomer?

A) It rotates plane-polarized light to the right.

B) It rotates plane-polarized light to the left.

C) It is a racemic form.

D) It is the mirror image of the corresponding (R)-enantiomer.

E) It has the highest priority group on the left.

Topic: General definitions

Section Reference 1: 5.3, 5.4, 5.8

Difficulty: Easy

22) Which compound would show optical activity?

A) cis-1,4-Dimethylcyclohexane

B) trans-1,4-Dimethylcyclohexane

C) cis-1,4-Dimethylcycloheptane

D) trans-1,4-Dimethylcycloheptane

E) More than one of these choices.

Topic: Optical activity

Section Reference 1: 4.13, 5.6, 5.8

Difficulty: Easy

23) Of the compounds which correspond to the general name "dichlorocyclobutane," how many are optically active?

A) 0

B) 1

C) 2

D) 3

E) 4

Topic: Optical activity

Section Reference 1: 4.13, 5.6, 5.8

Difficulty: Easy

24) The compounds whose molecules are shown below would have:

A) the same melting point.

B) different melting points.

C) equal but opposite optical rotations.

D) More than one of these choices.

E) None of these choices.

Topic: Optical activity

Section Reference 1: 5.7, 5.8

Difficulty: Easy

25) If a solution of a compound (30.0 g/100 mL of solution) has a measured rotation of +15º in a 2.0 dm tube, the specific rotation is:

A) +50

B) +25

C) +15

D) +7.5

E) +4.0

Topic: Optical activity

Section Reference 1: 5.8C

Difficulty: Easy

26) What can be said with certainty if a compound has [α]= -9.25 ?

A) The compound has the (S) configuration.

B) The compound has the (R) configuration.

C) The compound is not a meso form.

D) The compound possesses only one stereogenic center.

E) The compound has an optical purity of less than 100%.

Topic: Optical activity

Section Reference 1: 5.8, 5.9

Difficulty: Easy

27) In the absence of specific data, it can only be said that (R)-2-bromopentane is:

A) dextrorotatory (+) .

B) levorotatory (–) .

C) optically inactive.

D) achiral.

E) analogous in absolute configuration to (R)-2-chloropentane.

Topic: Optical activity

Section Reference 1: 5.8, 5.9

Difficulty: Medium

28) An alkane which can exhibit optical activity is:

A) Neopentane

B) Isopentane

C) 3-Methylpentane

D) 3-Methylhexane

E) 2,3-Dimethylbutane

Topic: Optical activity

Section Reference 1: 4.3, 5.8, 5.9

Difficulty: Easy

29) What is the percent composition of a mixture of (S)-(+)-2-butanol, [α] = +13.52, and (R)-(–)-2-butanol, [α] = –13.52, with a specific rotation [α] = +6.76?

A) 75% (R), 25% (S)

B) 25% (R), 75% (S)

C) 50% (R), 50% (S)

D) 67% (R), 33% (S)

E) 33% (R), 67% (S)

Topic: Optical activity

Section Reference 1: 5.9

Difficulty: Medium

30) What is the enantiomeric excess of a compound that shows a specific rotation [α] = +18.6, where the pure enantiomer has a reference value of [α] = +24.8?

A) 6.6%

B) 21.5%

C) 50%

D) 75%

E) 0%, racemic mixture

Topic: Optical activity

Section Reference 1: 5.9

Difficulty: Medium

31) The reaction of with H₂/Ni forms:

A) 2-methylheptane

B) (R)-2-methyl-5-heptanol

C) (S)-6-methyl-3-heptanol

D) (R)- and (S)-6-methyl-3-heptanol

E) Achiral 6,6-dimethyl-3-hexanol

Topic: Reaction stereochemistry

Section Reference 1: 5.10

Difficulty: Medium

32) The name of the product produced when cis-2-methyl-2-buten-1-ol is treated with H₂ in Pd/C is:

A) (R)-2-methyl-1-butanol

B) (S)-2-methyl-1-butanol

C) racemic mixture of 2-methyl-1-butanol

D) 2-methyl-1-butanol

E) None of these choices.

Topic: Reaction stereochemistry

Section Reference 1: 5.10

Difficulty: Medium

33) The name of the compound formed when 1,2-dimethylcyclohexene is treated with H₂ in Pd/C is:

A) cis-1,2-dimethylcyclohexane

B) trans-1,2-dimethylcyclohexane

C) mixture of cis- and trans-1,2-dimethylcyclohexane

D) meso-1,2-dimethylcyclohexane

E) none of these choices

Topic: Reaction stereochemistry

Section Reference 1: 5.10

Difficulty: Medium

34) How many stereogenic centers are there in Lovastatin (Mevacor®, a cholesterol-lowering drug)?

A) 4

B) 5

C) 6

D) 7

E) 8

Topic: General stereochemistry

Section Reference 1: 5.4, 5.11

Difficulty: Easy

35) Which of the following is a meso compound?

A) I

B) II

C) III

D) IV

E) V

Topic: Meso compounds

Section Reference 1: 5.12

Difficulty: Easy

36) Which of the following is (are) meso compound(s)?

A) I

B) II

C) III

D) Both II and III

E) Both I and III

Topic: Meso compounds

Section Reference 1: 5.12

Difficulty: Easy

37) Which of the following is (are) meso?

A) I

B) II

C) III

D) IV

E) Two of these choices.

Topic: Meso compounds

Section Reference 1: 5.12

Difficulty: Easy

38) Which molecule is a meso compound?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Meso compounds

Section Reference 1: 5.12

Difficulty: Easy

39) CH₃CHBrCH₂CHClCH₃ is the generalized representation of what number of stereoisomers?

A) 3

B) 4

C) 5

D) 6

E) 7

Topic: General stereochemistry

Section Reference 1: 5.12

Difficulty: Easy

40) For the generalized structure BrCH₂CHClCH₂CHClCH₂Br there exists what number of stereoisomers?

A) 2

B) 3

C) 4

D) 6

E) 8

Topic: General stereochemistry

Section Reference 1: 5.12

Difficulty: Easy

41) How many distinct dimethylcyclopropanes are there?

A) 2

B) 3

C) 4

D) 5

E) 6

Topic: General stereochemistry

Section Reference 1: 5.12

Difficulty: Easy

42) How many chiral stereoisomers can be drawn for CH₃CHFCHFCH(CH₃)₂?

A) 1

B) 2

C) 3

D) 4

E) 8

Topic: General stereochemistry

Section Reference 1: 5.12

Difficulty: Easy

43) Which statement is not true for a meso compound?

A) The specific rotation is 0.

B) There are one or more planes of symmetry.

C) A single molecule is identical to its mirror image.

D) More than one stereogenic center must be present.

E) The stereochemical labels, (R) and (S), must be identical for each stereogenic center.

Topic: Meso compounds

Section Reference 1: 5.12

Difficulty: Medium

44) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 4.8, 5.2, 5.4, 5.12

Difficulty: Medium

45) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 4.12, 5.2, 5.4, 5.12

Difficulty: Medium

46) The structures

represent:

A) a single compound.

B) enantiomers.

C) meso forms.

D) diastereomers.

E) conformational isomers.

Topic: Identifications and Comparisons

Section Reference 1: 4.12, 5.2, 5.4, 5.12

Difficulty: Medium

47) The two compounds shown below are:

A) identical.

B) enantiomers.

C) diastereomers.

D) conformational isomers.

E) meso forms.

Topic: Identifications and Comparisons

Section Reference 1: 4.12, 5.2, 5.4, 5.12

Difficulty: Medium

48) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 4.12, 5.2, 5.4, 5.12

Difficulty: Hard

49) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 4.12, 5.2, 5.4, 5.12

Difficulty: Hard

50) Which statement is true of 1,3-dimethylcyclobutane?

A) Only one form of the compound is possible.

B) Two diastereomeric forms are possible.

C) Two sets of enantiomers are possible.

D) Two enantiomeric forms and one meso compound are possible.

E) None of the previous statements is true.

Topic: General definitions

Section Reference 1: 4.13, 5.4, 5.12

Difficulty: Medium

51) Hexane and 3-methylpentane are examples of:

A) enantiomers.

B) stereoisomers.

C) diastereomers.

D) constitutional isomers.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

52) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

53) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

54) The molecules below are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) stereoisomers.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

55) The molecules shown are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

56) The molecules below are:

A) structural isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

57) The molecules below are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

58) The molecules below are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

59) The molecules below are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

60) The molecules below are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

61) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Easy

62) The molecules below are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

63) The molecules below are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

64) The molecules below are:

A) enantiomers.

B) diastereomers.

C) constitutional isomers.

D) two different conformations of the same molecule.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

65) The molecules below are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

66) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

67) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

68) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

69) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

70) The molecules shown are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

71) The molecules shown are:

A) enantiomers.

B) diastereomers.

C) constitutional isomers.

D) two conformations of the same molecule.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

72) The molecules shown are:

A) constitutional isomers.

B) enantiomers.

C) diastereomers.

D) identical.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

73) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

74) Which of the following are enantiomers of the compound (+)-camphor:

A) I only

B) I and II only

C) II only

D) I and III only

E) I, II and III

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

75) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

76) Which of the following compounds (I-IV) represent enantiomers?

A) I and II

B) II and III

C) III and IV

D) II and IV

E) III and I

Topic: General stereochemistry

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

77) Which compound (I-IV) is a meso compound?

A) I

B) II

C) III

D) IV

E) None of these choices.

Topic: General stereochemistry

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

78) Which compound (I-IV) is (2R,3R)-2,3-butanediol?

A) I

B) II

C) III

D) IV

E) None of these choices.

Topic: General stereochemistry

Section Reference 1: 5.2, 5.4, 5.7, 5.12

Difficulty: Medium

79) Which compounds (I-IV) form a set of stereoisomers?

A) I, II and III

B) II, III and IV

C) II and III

D) I, III and IV

E) I, II, III and IV

Topic: General stereochemistry

Section Reference 1: 5.2, 5.4, 5.7, 5.12

Difficulty: Medium

80) Which of the following substances is/are achiral?

A) I

B) II

C) III

D) IV

E) More than one of these choices.

Topic: Meso compounds

Section Reference 1: 5.1, 5.6, 5.12

Difficulty: Easy

81) Which molecule has a plane of symmetry?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Meso compounds

Section Reference 1: 5.6, 5.12

Difficulty: Easy

82) Which molecule has a plane of symmetry?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Meso compounds

Section Reference 1: 5.6, 5.12

Difficulty: Easy

83) Which compound does NOT possess a plane of symmetry?

A) I, II and V

B) I, III and IV

C) II, III and IV

D) III and IV

E) V

Topic: Meso compounds

Section Reference 1: 5.6, 5.12

Difficulty: Easy

84) Which molecule is a meso compound?

A) I and II

B) IV and V

C) II and III

D) I, II and III

E) None of these choices.

Topic: Meso compounds

Section Reference 1: 5.6, 5.12

Difficulty: Easy

85) The compounds whose molecules are shown below would have:

A) the same melting point.

B) different melting points.

C) equal but opposite optical rotations.

D) More than one of these choices.

E) None of these choices.

Topic: Optical activity

Section Reference 1: 5.7, 5.12

Difficulty: Easy

86) Which of the following molecules is achiral?

A) (2R,3R)-2,3-Dichloropentane

B) (2R,3S)-2,3-Dichloropentane

C) (2S,4S)-2,4-Dichloropentane

D) (2S,4R)-2,4-Dichloropentane

E) Two of these choices.

Topic: Meso compounds

Section Reference 1: 5.7, 5.12

Difficulty: Medium

87) Which is a meso compound?

A) (2R,3R)-2,3-Dibromobutane

B) (2R,3S)-2,3-Dibromopentane

C) (2R,4R)-2,4-Dibromopentane

D) (2R,4S)-2,4-Dibromopentane

E) (2R,4S)-2,4-Dibromohexane

Topic: Meso compounds

Section Reference 1: 5.7, 5.12

Difficulty: Medium

88) What is the correct stereochemistry for the indicated stereocenters in (+)-camphor?

A) 1R,4R

B) 1R,4S

C) 1S,4S

D) 1S,4R

E) None, molecule is not chiral.

Topic: Specific names

Section Reference 1: 5.7, 5.12

Difficulty: Hard

89) The Cahn-Ingold-Prelog stereochemical designations used for the following substance are:

A) 2R,4S

B) 2S,4R

C) 2R,4R

D) 2S,4S

E) The “R,S” terminology doesn't apply in this case.

Topic: Specific names

Section Reference 1: 5.7, 5.12

Difficulty: Medium

90) How many different compounds are there which correspond to the general name "3-(1-methylbutyl)cyclobutanol”?

A) 2

B) 4

C) 6

D) 8

E) None of these choices.

Topic: General stereochemistry

Section Reference 1: 5.7 and 5.12

Difficulty: Medium

91) (2R,4S)-2,4-Dichloropentane and (2S,4R)-2,4-dichloropentane are:

A) enantiomers.

B) diastereomers.

C) identical.

D) conformational isomers.

E) constitutional isomers.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.7, 5.12

Difficulty: Medium

92) The compounds whose molecules are shown below would have:

A) the same melting point.

B) different melting points.

C) equal but opposite optical rotations.

D) More than one of these choices.

E) None of these choices.

Topic: Optical activity

Section Reference 1: 5.6, 5.8, 5.12

Difficulty: Easy

93) The compounds whose structures are shown below would have:

A) the same melting point.

B) different melting points.

C) equal but opposite optical rotations.

D) More than one of these choices.

E) None of these choices.

Topic: Optical activity

Section Reference 1: 5.6, 5.8, 5.12

Difficulty: Easy

94) Which one of the following can exist in optically active forms?

A) cis-1,3-Dichlorocyclohexane

B) trans-1,3-Dichlorocyclohexane

C) cis-1,4-Dichlorocyclohexane

D) trans-1,4-Dichlorocyclohexane

E) cis-1,2-Dichlorocyclohexane

Topic: Optical activity

Section Reference 1: 4.13, 5.6, 5.12

Difficulty: Medium

95) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 4.8, 5.2, 5.4, 5.12, 5.13

Difficulty: Easy

96) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 4.8, 5.2, 5.4, 5.12, 5.13

Difficulty: Hard

97) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 4.8, 5.2, 5.4, 5.12, 5.13

Difficulty: Hard

98) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 4.8A, 5.2, 5.4, 5.12, 5.13

Difficulty: Hard

99) I and II are:

A) constitutional isomers.

B) enantiomers.

C) non-superposable mirror images.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, and 5.13

Difficulty: Easy

100) The two compounds shown below are:

A) enantiomers.

B) diastereomers.

C) constitutional isomers.

D) identical.

E) different but not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Easy

101) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Easy

102) Which pair of structures represents the same compound?

A) I and II

B) II and III

C) III and IV

D) III and V

E) IV and V

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Medium

103) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, and 5.13

Difficulty: Medium

104) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Medium

105) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Medium

106) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Medium

107) Which structure(s) represent(s) diastereomer(s) of I?

A) II

B) II and III

C) II and IV

D) III and V

E) IV and V

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Hard

108) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, and 5.13

Difficulty: Hard

109) I and II are:

A) constitutional isomers.

B) enantiomers.

C) identical.

D) diastereomers.

E) not isomeric.

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Hard

110) The molecule is properly named:

A) (3R,4S,5R)-3,5-Dichloro-4-methylhexane

B) (2S,3S,4S)-2,4-Dichloro-3-methylhexane

C) (2S,3R,4R)-2,4-Dichloro-3-methylhexane

D) (2S,3R,4S)-2,4-Dichloro-3-methylhexane

E) (2S,3S,4R)-2,4-Dichloro-3-methylhexane

Topic: Specific names

Section Reference 1: 4.3, 5.7, 5.12, 5.13

Difficulty: Medium

111) Which of these is not a correct Fischer projection formula of the (S) form of

3-bromo-1,1-dichloro-2-propanol?

A) I

B) II

C) III

D) IV

E) V

Topic: Specific names

Section Reference 1: 4.3, 5.7, 5.13

Difficulty: Medium

112) What is the IUPAC name of the following compound?

A) (1R,3R,5R)-1-bromo-3-chloro-5-fluorocyclohexane

B) (1R,3R,5S)-1-bromo-3-chloro-5-fluorocyclohexane

C) (1S,3S,5R)-1-bromo-3-chloro-5-fluorocyclohexane

D) (1S,3S,5S)-1-bromo-3-chloro-5-fluorocyclohexane

E) None of these choices.

Topic: Stereochemistry of Cyclic Compounds

Section Reference 1: 5.14

Difficulty: Hard

113) Which reaction must take place with retention of configuration at the stereogenic center?

A)

B)

C)

D) More than one of these choices.

E) None of these choices.

Topic: Reaction stereochemistry

Section Reference 1: 5.15

Difficulty: Easy

114) In which of the following reactions is the absolute configuration of the product likely to be the same as that of the reactant?

A)

B)

C)

D) All of these choices.

E) Two of these choices.

Topic: Reaction stereochemistry

Section Reference 1: 5.15

Difficulty: Medium

115) Which of the following reactions must occur with retention of configuration?

A)

B)

C)

D)

E)

Topic: Reaction Stereochemistry

Section Reference 1: 5.15

Difficulty: Medium

116) How is it possible to differentiate compounds in a racemic mixture?

A) by distilling of one isomer from the other

B) through the use of IR spectroscopy

C) chemical conversion to a diastereomeric mixture

D) how the mixture rotates in plane polarized light

E) it is impossible to differentiate the two compounds

Topic: Enantiomeric Resolution

Section 5.16

Difficulty: Easy

117) A solution of which of these allenes will rotate plane-polarized light?

A) I

B) II

C) III

D) IV

E) V

Topic: Optical activity

Section Reference 1: 5.18

Difficulty: Medium

118) How many optically active compounds are represented in the following compound?

A) 0

B) 1

C) 2

D) 3

E) 4

Topic: Optical activity

Section Reference 1: 5.18

Difficulty: Medium

119) Which of the following molecules is achiral?

A) I

B) II

C) III

D) IV

E) V

Topic: Identifications and Comparisons

Section Reference 1: 5.1, 5.4, 5.12 and 5.18

Difficulty: Medium

Question type: True/False

120) A molecule must possess at least one stereogenic center to be a chiral molecule.

Topic: Chiral Molecules

Section Reference 1: 5.3

Difficulty: Easy

121) A sample consisting of the pure R enantiomer of a compound will always rotate plane-polarized light in a clockwise direction.

Topic: General stereochemistry

Section Reference 1: 5.8

Difficulty: Easy

122) A chiral molecule was found to have a specific rotation of +19.5, thus we can conclude that the enantiomer of this compound will have a rotation that is equal and opposite in value.

Topic: Optical activity

Section Reference 1: 5.8, 5.9

Difficulty: Medium

123) A racemic mixture shows a specific rotation value of 0 because molecules in the mixture will not rotate plane-polarized light.

Topic: Optical activity

Section Reference 1: 5.8, 5.9

Difficulty: Medium

124) A racemic mixture will show a depressed boiling point as the impure mixture creates a lowering in the vapor pressure above the solution.

Topic: Physical properties of Enantiomers

Section Reference 1: 5.8, 5.9

Difficulty: Hard

125) A diastereomeric mixture can be very difficult to purify as both isomers have the same physical properties.

Topic: Resolution

Section Reference 1: 5.16

Difficulty: Easy

Question type: fill in the blank

126) An achiral molecule is one that is ____ upon its mirror image.

Topic: General stereochemistry

Section Reference 1: 5.1, 5.2

Difficulty: Easy

127) Enantiomers are stereoisomers whose molecules are ___.

Topic: General stereochemistry

Section Reference 1: 5.2

Difficulty: Easy

128) When discussing the stereochemical relationship of cis/trans isomers of cyclic compounds, we refer to them as ___.

Topic: General stereochemistry

Section Reference 1: 5.2

Difficulty: Medium

129) A chiral molecule is defined as one that is ___ on its mirror image.

Topic: General stereochemistry

Section Reference 1: 5.3

Difficulty: Easy

130) To be superposable, when one object is placed on top of another, ___.

Topic: General stereochemistry

Section Reference 1: 5.2, 5.3

Difficulty: Easy

131) The molecule of aspartame (Nutrasweet®), depicted below, has ___ ( how many? ) stereogenic centers.

Topic: General stereochemistry

Section Reference 1: 5.4

Difficulty: Easy

132) All molecules with a plane of symmetry are ___.

Topic: General stereochemistry

Section Reference 1: 5.6

Difficulty: Easy

133) When using the Cahn-Ingold-Prelog rules for prioritizing groups on a stereogenic carbon, priority is first assigned on the basis of ___.

Topic: General stereochemistry

Section Reference 1: 5.7

Difficulty: Easy

134) The compound shown below is an isomer of the asthma medication albuterol. Indicate whether the compound is (R)-albuterol or (S)-albuterol?

Topic: Nomenclature

Section Reference 1: 4.3, 5.7

Difficulty: Easy

135) Draw a dash-wedge structure for (R)-2,3,5-trimethylhexane

Topic: Nomenclature

Section Reference 1: 4.3, 5.7

Difficulty: Easy

136) Draw a dash-wedge structure for (1R)-1-bromo-1,3,3-trimethylcyclohexane

Topic: Nomenclature

Section Reference 1: 4.4, 5.7

Difficulty: Easy

137) Draw a dash-wedge structure for (R)-3-methyl-5-hexen-3-ol

Topic: Nomenclature

Section Reference 1: 4.3, 4.5, 5.7

Difficulty: Medium

138) Draw a dash-wedge structure for (R)-5-methylhept-2-yne

Topic: Nomenclature

Section Reference 1: 4.3, 4.6, 5.7

Difficulty: Easy

139) Draw a dash-wedge structure for (S,trans)-5-fluoro-2,2-dimethylhex-3-ene

Topic: Nomenclature

Section Reference 1: 4.3, 4.6, 5.7

Difficulty: Medium

140) Draw a dash-wedge structure for (R,cis)-hept-3-en-5-yn-2-ol

Topic: Nomenclature

Section Reference 1: 4.3, 4.5, 4.6, 5.7

Difficulty: Medium

141) Enantiomers have ___ physical properties.

Topic: General stereochemistry

Section Reference 1: 5.8

Difficulty: Easy

142) The device that is used for measuring the effect of optically active compounds on plane-polarized light is called a ___.

Topic: General stereochemistry

Section Reference 1: 5.8

Difficulty: Medium

143) If a sample is said to contain a 98.0% enantiomeric excess of the compound (+)-camphor, what would be the observed specific rotation if the pure (+)-camphor was found to have a rotation of 44.1?

Topic: Optical activity

Section Reference 1: 5.8, 5.9

Difficulty: Easy

144) An equimolar mixture of two enantiomers is called a ___.

Topic: General stereochemistry

Section Reference 1: 5.9

Difficulty: Easy

145) X and Y are enantiomers with chemical formula C₆H₁₀. A racemic mixture of X and Y treated with excess H₂ and Pd/C was converted to a single compound Z (C₆H₁₂) which did not show optical activity. Suggest structure for X, Y and Z.

Topic: Synthesis using Chiral Molecules

Section Reference 1: 5.10

Difficulty: Medium

146) The drug Crixivan (an HIV protease inhibitor) depicted below, has ___ stereogenic centers.

Topic: General stereochemistry

Section Reference 1: 5.4, 5.11

Difficulty: Easy

147) A molecule that contains stereogenic carbons but is nonetheless achiral is referred to as a ___.

Topic: General stereochemistry

Section Reference 1: 5.12

Difficulty: Medium

148) A meso compound has ___ chiral center(s) , and is ___ upon its mirror image.

Topic: General stereochemistry

Section Reference 1: 5.12

Difficulty: Easy

149) What is the complete IUPAC name of the following substance? (Remember to give stereochemical details, as relevant.)

Topic: Nomenclature

Section Reference 1: 4.4, 5.7, 5.12

Difficulty: Medium

Question type: molecular drawing

150. Draw a dash-wedge structure for (2S,3S)-3-methylpent-4-en-2-ol

Topic: Nomenclature

Section Reference 1: 4.3, 4.5, 5.7, 5.12

Difficulty: Medium

151) Draw a dash-wedge structure for (3R,6R)-3-bromo-6-methylcyclohex-1-ene

Topic: Nomenclature

Section Reference 1: 4.3, 4.5, 5.7, 5.12

Difficulty: Medium

152) Draw a dash-wedge structure for (3R,4R)-4-bromo-1,3-dimethylcyclohex-1-ene

Topic: Nomenclature

Section Reference 1: 4.3, 4.5, 5.7, 5.12

Difficulty: Medium

153) Draw a dash-wedge structure for (2R,3S)-2-chloro-3-methylpentane

Topic: Nomenclature

Section Reference 1: 4.3, 5.7, 5.12

Difficulty: Easy

154) Draw a dash-wedge structure for (3R,4S)-4,6-dimethylheptan-3-ol

Topic: Nomenclature

Section Reference 1: 4.3, 5.7, 5.12

Difficulty: Easy

155) Draw a dash-wedge structure for (2R,3S)-2-bromo-3-chlorohexane

Topic: Nomenclature

Section Reference 1: 4.3, 5.7, 5.12

Difficulty: Easy

156) Draw a dash-wedge structure for (3S,4R)-4-fluoro-2,4-dimethylheptan-3-ol

Topic: Nomenclature

Section Reference 1: 4.3, 5.7, 5.12

Difficulty: Medium

157) Draw a dash-wedge structure for (2R,3R)-3-phenylbutan-2-ol

Topic: Nomenclature

Section Reference 1: 4.3, 5.7, 5.12

Difficulty: Hard

158) Draw a dash-wedge structure for (2R,4S)-2,4-dibromo-2-chloropentane

Topic: Nomenclature

Section Reference 1: 4.3, 5.7, 5.12

Difficulty: Hard

159) Draw a dash-wedge structure for (2S,3R)-3-bromo-6,6-dimethyloct-7-en-2-ol

Topic: Nomenclature

Section Reference 1: 4.3, 4.5, 5.7, 5.12

Difficulty: Medium

160) Draw a dash-wedge structure for (1R,2S,3S)-3-bromo-2-vinylcyclohexanol

Topic: Nomenclature

Section Reference 1: 4.4, 4.5, 5.7, 5.12

Difficulty: Hard

161) Draw a dash-wedge structure for (3S,4R)-4-chloro-3,5-dimethylhex-1-yne

Topic: Nomenclature

Section Reference 1: 4.3, 4.6, 5.7, 5.12

Difficulty: Medium

Question type: essay

162) What is the complete IUPAC name of the following substance? (Remember to give stereochemical details, as relevant.)

Topic: Nomenclature

Section Reference 1: 4.3, 4.5, 5.7, 5.12

Difficulty: Medium

163) What is the complete IUPAC name of the following substance? (Remember to give stereochemical details, as relevant.)

Topic: Nomenclature

Section Reference 1: 4.3, 4.5, 5.7, 5.12

Difficulty: Hard

164) Draw a dash-wedge structure for (1R,4R)-1,4-dibromo-1-chloro-1-fluoropentane

Topic: Nomenclature

Section Reference 1: 4.3, 5.7, 5.12

Difficulty: Hard

165) What is the complete IUPAC name of the following substance? (Remember to give stereochemical details, as relevant.)

Topic: Nomenclature

Section Reference 1: 4.3, 4.5, 4.6, 5.7, 5.12

Difficulty: Hard

166) What is the complete IUPAC name of the following substance? (Remember to give stereochemical details, as relevant.)

Topic: Nomenclature

Section Reference 1: 4.3, 4.8A, 5.7, 5.12

Difficulty: Hard

167) What is the complete IUPAC name of the following substance? (Remember to give stereochemical details, as relevant.)

Topic: Nomenclature

Section Reference 1: 4.4, 5.7, 5.12

Difficulty: Easy

Question type: Molecular Drawing

168) Draw a dash-wedge structure for (1S,3R)-1-ethyl-1,3-dimethylcyclopentane

Topic: Nomenclature

Section Reference 1: 4.4, 5.7, 5.12

Difficulty: Medium

169) Draw a dash-wedge structure for (1R,3R)-1,3-dibromo-1,3-dimethylcyclohexane

Topic: Nomenclature

Section Reference 1: 4.4, 5.7, 5.12

Difficulty: Medium

170) Draw a dash-wedge structure for (1S,2S,5R)-5-methyl-2-propylcyclohexanol

Topic: Nomenclature

Section Reference 1: 4.4, 5.7, 5.12

Difficulty: Medium

171) Draw dash-wedge structures for all stereoisomers of 1-bromo-3-isopropylcyclohexane, giving stereochemical details for each structure.

Topic: Stereoisomers

Section Reference 1: 4.4, 5.7, 5.12

Difficulty: Medium

172) Draw a dash-wedge structure for (1S,2R,3R)-1-tert-butyl-3-chloro-2-methylcyclohexane

Topic: Nomenclature

Section Reference 1: 4.4, 5.7, 5.12

Difficulty: Hard

173) What is the complete IUPAC name of the following substance? (Remember to give stereochemical details, as relevant.)

Topic: Nomenclature

Section Reference 1: 4.4, 5.7, 5.12

Difficulty: Hard

Question type: Essay

174) What is the IUPAC name of the following compound?

Topic: Nomenclature

Section Reference 1: 4.4, 5.7, 5.12

Difficulty: Hard

Question type: Molecular Drawing

175) Draw a dash-wedge structure for (3S,5R)-5-chloro-3-isopropylcyclohex-1-ene

Topic: Nomenclature

Section Reference 1: 4.5, 5.7, 5.12

Difficulty: Medium

Question type: essay

176) What is the complete IUPAC name of the following substance? (Remember to give stereochemical details, as relevant.)

Topic: Nomenclature

Section Reference 1: 4.3, 5.7, 5.12, 5.13

Difficulty: Medium

Question type: Molecular Drawing

177) Draw Fischer projection formulas for all stereoisomers of 2,4-dibromohexane, giving stereochemical details for each structure.

Topic: Fischer projections

Section Reference 1: 4.3, 5.7, 5.12, 5.13

Difficulty: Hard

178) Draw the Fischer projection of the following compound with the lowest priority groups on each chiral carbon in the back: (3R,4S)-4-bromo-4-chloro-3-heptanol.

Topic: Fischer projections

Section Reference 1: 4.3, 5.7, 5.12, 5.13

Difficulty: Hard

179) Draw a Fischer projection formula of (R)-6-bromo-1-hexen-3-ol.

Topic: Fischer projections

Section Reference 1: 4.3, 4.5, 5.7, 5.12, 5.13

Difficulty: Medium

180) Draw Fischer projection formulas for all stereoisomers of 2,4-dimethyl-3-hexanol, giving stereochemical details for each structure.

Topic: Fischer projections

Section Reference 1: 4.4, 5.7, 5.12, 5.13

Difficulty: Hard

181) Which molecule is chiral?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.1, 5.4

Difficulty: Easy

182) Which molecule is chiral?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Identifications and Comparisons

Section Reference 1: 5.1, 5.4

Difficulty: Easy

183) Achiral molecules are represented by:

A) I, II, III, IV and V

B) I, II, III and IV

C) I and II

D) III and IV

E) I, II, and V

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4

Difficulty: Medium

184) Which compound would not show optical activity?

A) cis-1,4-Dimethylcyclohexane

B) trans-1,4-Dimethylcyclohexane

C) cis-1,4-Dimethylcycloheptane

D) trans-1,4-Dimethylcycloheptane

E) More than one of these choices.

Topic: Optical activity

Section Reference 1: 4.13, 5.6, 5.8

Difficulty: Easy

185) Which of the following are NOT enantiomers of the compound (+)-camphor:

A) I only

B) I and II only

C) II only

D) I and III only

E) I, II and III

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

186) Which of the following compounds (I-IV) represent a constitutional isomer of the other compounds?

A) I

B) II

C) III

D) IV

E) None of these choices.

Topic: General stereochemistry

Section Reference 1: 5.2, 5.4, 5.12

Difficulty: Medium

187) Which of the following substances is/are chiral?

A) I

B) II

C) III

D) IV

E) More than one of these choices.

Topic: Meso compounds

Section Reference 1: 5.1, 5.6, 5.12

Difficulty: Easy

188) Which molecule does NOT have a plane of symmetry?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Meso compounds

Section Reference 1: 5.6, 5.12

Difficulty: Easy

189) Which molecule does NOT have a plane of symmetry?

A) I

B) II

C) III

D) More than one of these choices.

E) None of these choices.

Topic: Meso compounds

Section Reference 1: 5.6, 5.12

Difficulty: Easy

190) Which compound possess a plane of symmetry?

A) I, II and V

B) I, III and IV

C) II, III and IV

D) III and IV

E) V

Topic: Meso compounds

Section Reference 1: 5.6, 5.12

Difficulty: Easy

191) Which molecule is NOT a meso compound?

A) I and II

B) IV and V

C) II and III

D) I, II and III

E) All of these choices.

Topic: Meso compounds

Section Reference 1: 5.6, 5.12

Difficulty: Easy

192) How many different stereoisomers are represented in compounds (I-V)?

A) 1

B) 2

C) 3

D) 4

E) 5

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Medium

193) Which structure represents an enantiomer of I?

A) II

B) III

C) IV

D) V

E) None of these choices

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Hard

194) Which structure represents the same compound as I?

A) II

B) III

C) IV

D) V

E) None of these choices

Topic: Identifications and Comparisons

Section Reference 1: 5.2, 5.4, 5.12, 5.13

Difficulty: Hard