Chapter 5 TB

11) How many asymmetric carbon atoms are present in the following compound?

1

5) How many enantiomers are there of the molecule shown below? A) 0 B) 1 C) 2 D) 3 E) 6

1

34) How many asymmetric carbons are present in the compound below?

2

61) Which of the following configurations corresponds to the structure below? A) (4R, 5R) B) (4R, 5S) C) (4S, 5R) D) (4S, 5S)

(4R, 5R)

35) How many asymmetric carbons are present in the compound below?

3-ethyl-2,2,4-trimethylpentane

41) Which of the following structures are achiral and meso? A) 1 B) 2 C) 3 D) 4

4

15) How many asymmetric carbons are present in the compound below?

5

43) How many asymmetric carbons are present in the compound below?

5

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

Enantiomers

6) Which of the following incorrectly describes cis-1,2-dimethylcyclopentane? A) It is a meso compound. B) It is achiral. C) It contains two asymmetric carbons. D) Its diastereomer is trans-1,2-dimethylcyclopentane. E) It has an enantiomer.

It has an enantiomer.

49) Assign the proper configurational label, R or S, to the chiral carbon in the molecule shown below.

S

22) Is the mirror image of the following molecule an enantiomer or is it superimposable with it?

Superimposable. The molecule is achiral.

28) Is the molecule shown below chiral or achiral? CH3CH2CH(CH3)CH2CH3

achiral

29) Is the molecule shown below chiral or achiral?

achiral

33) Is the molecule shown below chiral or achiral?

chiral

2) What term describes the structural relationship between cis-1,2-dimethylcyclopentane and trans-1,3-dimethylcyclopentane? A) not isomers B) constitutional isomers C) enantiomers D) diastereomers E) conformers

constitutional isomers

3) What term describes the structural relationship between (2R,3R,4S)-2,3,4-trichloroheptane and (2S,3S,5R)-2,3,5-trichloroheptane? A) not isomers B) constitutional isomers C) enantiomers D) diastereomers E) conformers

constitutional isomers

4) What is the structural relationship between the two molecule shown below? A) constitutional isomers B) enantiomers C) diastereomers D) conformational isomers E) not isomers

constitutional isomers

20) What term describes the structural relationship between (2R,3R,4S)-2,3,4-trichloroheptane and (2S,3S,4R)-2,3,4-trichloroheptane? A) not isomers B) constitutional isomers C) enantiomers D) diastereomers E) conformers

enantiomers

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

enantiomers

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

enantiomers

32) Is the molecule shown below chiral or achiral?

achiral

10) Is the molecule shown below chiral or achiral? (CH3)3CCH(CH3)2

achiral

12) How many asymmetric carbon atoms are present in the following compound? A) 0 B) 1 C) 2 D) 3 E) 4

0

18) How many asymmetric carbon atoms are present in the molecule shown? A) 0 B) 1 C) 2 D) 3 E) 4

1

13) How many asymmetric carbons are present in the compound below?

1

31) Consider the four substituents below. Order them in decreasing priority according to the Cahn-Ingold-Prelog priority system. (Highest priority is first, lowest is last.) -D, -H, -CH3, -CH2CH3

1: -CH2CH3 2: -CH3 3: -D 4: -H

30) Consider the four substituents below. Order them in decreasing priority according to the Cahn-Ingold-Prelog priority system. (Highest priority is first, lowest is last.) -CH=CH2, -C(CH3)3, -CH2OH, -COOH

1: -COOH 2: -CH2OH 3: -C(CH3)3 4:-CH=CH2

19) How many asymmetric carbon atoms are present in the molecule shown? A) 0 B) 1 C) 2 D) 3 E) 4

2

38) Is the molecule shown below chiral or achiral?

achiral

39) Is the molecule shown below chiral or achiral?

achiral

1) ________ are isomers which have the same bonding sequence but differ in the orientation of their atoms in space.

Stereoisomers

25) Which of the statements below correctly 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 form. E) None of the above

The molecule might be a meso form.

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

The same compound

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

The same compound

42) Does the molecule shown below contain asymmetric carbon atoms? Is this molecule chiral?

Yes, the molecule contains 4 asymmetric carbon atoms. No, the molecule is not chiral since it is superimposable with its mirror image.

14) How many asymmetric carbons are present in the compound below?

none