Test Bank for Organic Chemistry 8th Edition by Bruice – Test Bank

$20.00

Description

Test Bank for Organic Chemistry 8th Edition by Bruice – Test Bank

 

Sample  Questions

 

 

Organic Chemistry, 8e (Bruice)

Chapter 3   An Introduction to Organic Compounds: Nomenclature, Physical Properties, and Structure

 

1) Which of the following is a tertiary amine?

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

Answer:  E

Section:  3-7

MCAT:  19.1

 

2) There are 8 isomers that have the molecular formula C5H11Br. How many of these are tertiary alkyl bromides?

  1. A) 0
  2. B) 1
  3. C) 2
  4. D) 3
  5. E) 8

Answer:  B

Section:  3-4

MCAT:  1.1, 3.2, 6.1

GLO:  G2

 

3) Which of the following is sec-butyl alcohol?

  1. A) CH3CH2CH2CH2OH
  2. B) CH3CH(OH)CH2CH3
  3. C) (CH3)2CHCH2OH
  4. D) (CH3)2CHOH
  5. E) (CH3)2CHOCH3

Answer:  B

Section:  3-6

MCAT:  10.1

 

4) Identify the number of tertiary carbons in the following structure.

  1. A) 2
  2. B) 3
  3. C) 4
  4. D) 5
  5. E) 6

Answer:  B

Section:  3-1

 

 

5) What is the common name for the following structure?

  1. A) isobutane
  2. B) isopropylmethane
  3. C) t-Butane
  4. D) n-Butane
  5. E) sec-Butane

Answer:  A

Section:  3-2

6) Give the IUPAC name for the following structure.

  1. A) 2-methyl-3-ethylheptane
  2. B) 3-ethyl-2-methylheptane
  3. C) 5-Isopropyloctane
  4. D) 4-Isopropyloctane
  5. E) 2-methyl-3-propylheptane

Answer:  D

Section:  3-2

MCAT:  3.1

 

7) There is something wrong with the following name. Write the structure and correct the name: 2-ethylpropane.

Answer:  The correct name is 2-methylbutane.

Section:  3-2

MCAT:  3.1

 

 

8) Give structures for the three isomers with molecular formula C5H12 and provide the common name of each.

Answer:

Section:  3-2

MCAT:  1.1, 3.1, 3.2

 

9) Provide an acceptable name for the alkane shown below.

CH3CH2CH2CH2CH2CH3

Answer:  hexane or n-hexane

Section:  3-2

MCAT:  3.1

10) Provide an acceptable name for the alkane shown below.

Answer:  2,5-dimethylheptane

Section:  3-2

MCAT:  3.1

 

11) Provide an acceptable name for the alkane shown below.

Answer:  5-sec-butyl-2,2-dimethylnonane or

2,2-dimethyl-5-(1-methylpropyl) nonane

Section:  3-2

MCAT:  3.1

 

12) Provide an acceptable name for the alkane shown below.

Answer:  4-isopropyldecane or 4-(1-methlyethyl) decane

Section:  3-2

MCAT:  3.1

 

13) Provide an acceptable name for the alkane shown below.

Answer:  3-ethyl-6-methyl-5-propylnonane

Section:  3-2

MCAT:  3.1

14) Provide an acceptable name for the alkane shown below.

Answer:  3-ethyl-4, 4-dimethylheptane

Section:  3-2

MCAT:  3.1

 

15) Draw an acceptable structure for 4-t-butyloctane.

Answer:

Section:  3-2

MCAT:  3.1

 

16) Draw an acceptable structure for 3-ethyl-3-methylhexane.

Answer:

Section:  3-2

MCAT:  3.1

 

 

17) Draw an acceptable structure for 4-isopropyl-2-methylheptane.

Answer:

Section:  3-2

MCAT:  3.1

18) Draw an acceptable structure for 6-ethyl-2,6, 7-trimethyl-5-propylnonane.

Answer:

Section:  3-2

MCAT:  3.1

 

19) Provide an acceptable name for the alkane shown below.

Answer:  2,2,3,6-tetramethylheptane

Section:  3-2

MCAT:  3.1

 

20) Provide an acceptable name for the alkane shown below.

Answer:  6-ethyl-2-methyl-5-propyldecane

Section:  3-2

MCAT:  3.1

 

 

21) Give the systematic name of the alkane shown below.

Answer:  4-ethyl-2,2,7-trimethylnonane

Section:  3-2

MCAT:  3.1

22) Give the systematic name of the alkane shown below.

Answer:  3-ethyl-4-isopropyloctane

Section:  3-2

MCAT:  3.1

 

23) Name the compound.

  1. A) 2-ethyl-3-propylpentane
  2. B) 2,3-diethylhexane
  3. C) 4-ethyl-5-methylheptane
  4. D) 4-methyl-3-ethylheptane
  5. E) 4-ethyl-3-methylheptane

Answer:  E

Section:  3-2

 

 

24) Provide an acceptable name for the compound shown below.

Answer:  3,3,5-trimethylheptane

Section:  3-2

 

25) Provide an acceptable name for the compound shown below.

Answer:  5-ethyl-3,3-dimethyloctane

Section:  3-2

MCAT:  3.1

26) Give the systematic name of the cycloalkane shown below.

Answer:  4-butyl-1,2-dimethylcyclohexane

Section:  3-3

MCAT:  3.1

 

27) Draw an acceptable structure for sec-butylcyclopentane.

Answer:

Section:  3-3

MCAT:  3.1

 

 

28) Provide the systematic name of the compound shown.

Answer:  4-butyl-1-ethyl-2-methylcycloheptane

Section:  3-3

MCAT:  3.1

29) Give the formula.

  1. A) C8H8
  2. B) C8H10
  3. C) C8H12
  4. D) C8H14
  5. E) C8H16

Answer:  D

Section:  3-3

 

30) Name the compound.

  1. A) 2-cyclopentyl-4-methylhexane
  2. B) 5-cyclopentyl-3-methylhexane
  3. C) 1-cyclopentyl-1,3-dimethylpentane
  4. D) 2-cyclopentyl-4-methylheptane
  5. E) 5-cyclopentyl-3-methylheptane

Answer:  A

Section:  3-3

MCAT:  3.1

 

31) Determine the number of hydrogens in limonene.

  1. A) 8
  2. B) 10
  3. C) 12
  4. D) 16
  5. E) 18

Answer:  D

Section:  1-4

32) Provide an acceptable name for the compound shown below.

Answer:  isobutylcycloheptane

Section:  3-3

MCAT:  3.1

 

33) Provide an acceptable name for the compound shown below.

Answer:  3,3-dibromo-1-chloroheptane

Section:  3-4

MCAT:  3.1

 

 

34) Provide the common name of the compound.

  1. A) neoheptyl chloride
  2. B) sec-heptyl chloride
  3. C) isoheptyl chloride
  4. D) tert-heptyl chloride
  5. E) n-heptyl chloride

Answer:  C

Section:  3-4

MCAT:  6.1

35) Provide the IUPAC name of the compound.

  1. A) 2-methylheptane
  2. B) 1-chloro-5-methylhexane
  3. C) 6-chloro-2-methylhexane
  4. D) 1,1-dimethyl-5-chloropentane

Answer:  B

Section:  3-4

MCAT:  6.1

 

36) What is the common name for the following structure?

  1. A) isobutyl bromide
  2. B) t-Butyl bromide
  3. C) neobutyl bromide
  4. D) sec-Butyl bromide
  5. E) isopropyl methyl bromide

Answer:  B

Section:  3-4

MCAT:  6.1

 

 

37) Give the IUPAC name for the following compound.

  1. A) 1-chloro-2-methylcyclohexane
  2. B) 1-methyl-2-chlorocyclohexane
  3. C) 1-chloro-5-methylcyclohexane
  4. D) 1-methyl-5-chlorocyclohexane
  5. E) 1, 2-chloromethylcyclohexane

Answer:  A

Section:  3-4

MCAT:  6.1

38) Which of the following is diisopropyl ether?

  1. A) CH3CH2CH2–O–CH2CH2CH3
  2. B)
  3. C) CH3CH2CH2OCH(CH3)2
  4. D) (CH3)3COC(CH3)3
  5. E) (CH3)2CHOCH(CH3)2

Answer:  E

Section:  3-5

MCAT:  14.1

 

39) Draw all ethers with molecular formula C4H10O.

Answer:

Section:  3-5

MCAT:  1.1, 14.1

 

 

40) Draw all possible constitutional isomers for C2H6O and give common names for each structure.

Answer:

Section:  3-5, 3-6

MCAT:  1.1, 3.2, 10.1, 14.1

41) Give the IUPAC name for the following structure.

  1. A) 3-chloro-6-methylcyclohexanol
  2. B) 2-methyl-5-chlorocyclohexanol
  3. C) 1-chloro-4-methylcyclohexanol
  4. D) 5-chloro-2-methylcyclohexanol
  5. E) 2-methyl-3-chlorocyclohexanol

Answer:  D

Section:  3-6

MCAT:  6.1, 10.1

 

42) Which of the following compounds does not have the molecular formula C6H14O?

  1. A) 1-hexanol
  2. B) 2-hexanol
  3. C) 3-methyl-2-pentanol
  4. D) 3-methyl-3-pentanol
  5. E) cyclohexanol

Answer:  E

Section:  3-6

MCAT:  1.1, 3.2, 10.1

 

 

43) Give the structure of isopentyl alcohol.

Answer:

Section:  3-6

MCAT:  10.1

 

44) Provide the systematic name of the compound shown.

Answer:  6,7-dimethyl-3-octanol

Section:  3-6

MCAT:  10.1

45) Name the structure.

Answer:  6-chloro-2-hexanol

Section:  3-6

MCAT:  6.1, 10.1

 

46) Provide an acceptable name for the compound shown below.

Answer:  5-ethyl-2-methylcyclohexanol

Section:  3-6

MCAT:  10.1

 

 

47) Provide an acceptable name for the compound shown below.

Answer:  N-ethyl-2-pentanamine or N-ethylpentan-2-amine

Section:  3-7

MCAT:  19.1

 

48) Classify the following amines as primary, secondary, or tertiary.

Answer:  primary, secondary, secondary

Section:  3-7

MCAT:  19.1

49) Provide the common name of the compound.

  1. A) tert-butyldimethylamine
  2. B) isobutyldimethylamine
  3. C) neobutyldimethylamine
  4. D) sec-butyldimethylamine
  5. E) n-butyldimethylamine

Answer:  A

Section:  3-7

MCAT:  19.1

 

 

50) Provide the IUPAC name of the compound.

  1. A) N,N,1,1-tetramethylethanamine
  2. B) N,N-dimethyl-2-butanamine
  3. C) N,N,2-trimethyl-1-propanamine
  4. D) N,N,2-trimethylpropanamine
  5. E) N,N,2-trimethyl-2-propanamine

Answer:  E

Section:  3-7

MCAT:  19.1

 

51) Provide the IUPAC name of the compound.

H2NCH2CH2CH2CH2OH

Answer:  4-amino-1-butanol

Section:  3-7

MCAT:  10.1, 19.1

 

52) Draw the structure of 3-chloro-N-ethyl-2-hexanamine.

Answer:

Section:  3-7

MCAT:  6.1, 19.1

53) Give the structure of tetramethylammonium chloride.

Answer:

Section:  3-7

MCAT:  19.1

 

 

54) Draw the structure of N-ethyl-5-methyl-3-hexanamine.

Answer:

Section:  3-7

MCAT:  19.1

 

55) Fluorine is more electronegative than chlorine yet the carbon-fluorine bond in CH3-F is shorter than CH3-Cl. Explain.

Answer:  Chlorine is a larger atom than fluorine and uses a 3p rather than 2p orbital. The overlap of a 2sp3 orbital with a 3p orbital is not as good as the overlap of a 2sp3 orbital with a 2p orbital, causing the bond to be longer and weaker.

Section:  3-8

MCAT:  2.7

GLO:  G2

 

56) Identify the compound with the highest bond angle.

  1. A) the C-O-C bond in an ether
  2. B) the C-N-C bond in a secondary amine
  3. C) the C-N-C bond in a quaternary amine
  4. D) the C-O-C bond in an alcohol
  5. E) They are all equal.

Answer:  C

Section:  3-8

MCAT:  10.1, 14.1, 19.1

GLO:  G2

57) Identify the compound with the highest boiling point.

  1. A) CH3CH2OCH2CH3
  2. B) CH3CH2CH2CH2OH
  3. C) CH3CH2CH2CH2NH2
  4. D) CH3CH2CH2CH2Cl
  5. E) CH3CH2CH2CH2Br

Answer:  B

Section:  3-9

MCAT:  2.5

 

 

58) Identify the compound(s) that do not have hydrogen bonding. You may choose more than one answer.

  1. A) CH3CH2CH2NHCH3
  2. B) CH3CH2CH2CH2Cl
  3. C) CH3CH2CH2CH2NH2
  4. D) CH3CH2CH2CH2OH
  5. E) CH3CH2CH2OCH3

Answer:  B, E

Section:  3-9

MCAT:  2.5

 

59) Which of the following will have the lowest boiling point?

  1. A) CH3Cl
  2. B) CH4
  3. C) CH2Cl2
  4. D) CHCl3
  5. E) CCl4

Answer:  B

Section:  3-9

MCAT:  2.5

 

60) Which of the compounds below will form hydrogen bonds between its molecules?

  1. A) CH3CH2CH2F
  2. B) CH3CH2CH2CH3
  3. C) (CH3)3N
  4. D) CH3CH2OCH3
  5. E) CH3NHCH2CH3

Answer:  E

Section:  3-9

MCAT:  2.5

GLO:  G2

 

61) Which of the following has the greatest van der Waal’s interaction between molecules of the same kind?

  1. A)
  2. B) CH3CH2CH2CH3
  3. C)
  4. D) CH3CH2CH2CH2CH3
  5. E)

Answer:  D

Section:  3-9

 

 

62) Which of the following has the lowest boiling point?

  1. A) CH3CH2CH2CH2CH2CH3
  2. B)
  3. C)
  4. D)
  5. E) CH3CH2CH2CH2CH2CH2CH3

Answer:  C

Section:  3-9

MCAT:  3.3

63) Which of the following has the greatest solubility in CH3CH2CH2CH3?

  1. A) CH3OH
  2. B) CH3O- Na+
  3. C) CH3NH2
  4. D) CH3OCH3
  5. E) (CH3)3CH

Answer:  E

Section:  3-10

MCAT:  2.5

 

64) Which of the following is the most soluble in H2O?

  1. A) CH3OCH3
  2. B) CH3CH2OH
  3. C) CH3CH2Cl
  4. D) CH3CH2CH3
  5. E) CH3CHO

Answer:  B

Section:  3-10

MCAT:  2.5

 

 

65) Which of the following would have the highest boiling point?

  1. A) CH3CH2—O—CH2CH2—O—CH3
  2. B) CH3—O—CH2CH2CH2—O—CH3
  3. C) HO—CH2CH2CH2CH2—OH
  4. D) CH3CH2—O—CH2—O—CH2CH3
  5. E)

Answer:  C

Section:  3-9

MCAT:  14.1

 

66) Consider the three isomeric alkanes n-hexane, 2, 3-dimethylbutane, and 2-methylpentane. Which of the following correctly lists these compounds in order of increasing boiling point?

  1. A) 2, 3-dimethylbutane < 2-methylpentane < n-hexane
  2. B) 2-methylpentane < n-hexane < 2, 3-dimethylbutane
  3. C) 2-methylpentane < 2, 3-dimethylbutane < n-hexane
  4. D) n-hexane < 2-methylpentane < 2, 3-dimethylbutane
  5. E) n-hexane < 2, 3-dimethylbutane < 2-methylpentane

Answer:  A

Section:  3-9

MCAT:  3.1, 3.3

67) What is the strongest intermolecular force present in liquid ethanol?

  1. A) induced dipole-induced dipole
  2. B) dipole-dipole, specifically hydrogen bonding
  3. C) dipole-dipole, but not hydrogen bonding
  4. D) ion-dipole
  5. E) ion-ion

Answer:  B

Section:  3-9

MCAT:  2.5, 10.1

 

68) Assuming roughly equivalent molecular weights, which of the following would have the highest boiling point?

  1. A) a tertiary amine
  2. B) a quaternary ammonium salt
  3. C) an alcohol
  4. D) an ether
  5. E) an alkyl chloride

Answer:  B

Section:  3-9

MCAT:  2.5

 

 

69) Explain why the molecule shown below has a lower boiling point than CH3CH2CH2CH3.

Answer:  CH3CH2CH2CH3 has greater van der Waals forces because it has a greater contact area than isobutane. Therefore, the boiling point of CH3CH2CH2CH3 is higher.

Section:  3-9

MCAT:  2.5, 3.3

 

70) Primary and secondary amines exhibit hydrogen bonding; tertiary amines do not. Explain.

Answer:  The nitrogen in a tertiary amine is not attached to a hydrogen. Recall that for a molecule to exhibit hydrogen bonding it must have a hydrogen attached to a highly electronegative atom such as F, N, or O.

Section:  3-9

MCAT:  2.5, 19.1, 19.4

 

71) Explain why trimethylamine, (CH3)3N:, has a considerably lower boiling point than propylamine CH3CH2CH2NH2, even though both compounds have the same molecular formula.

Answer:  Since hydrogen bonding is possible for propylamine and not for trimethylamine, the boiling point is higher for propylamine.

Section:  3-9

MCAT:  19.4

72) Which of the molecules below has the higher boiling point? Briefly explain your choice.

CH3CH2CH2OH or CH3CH2OCH3

Answer:  CH3CH2CH2OH has the higher boiling point since it is capable of intermolecular hydrogen bonding.

Section:  3-9

MCAT:  2.5, 10.2, 14.1

 

73) Would you expect sodium chloride (NaCl) to be highly soluble in the organic solvent hexane (CH3CH2CH2CH2CH2CH3)? Briefly explain your answer.

Answer:  One would not expect NaCl to be highly soluble in hexane. NaCl is an ionic solid (i.e., a very polar material) while hexane is nonpolar. Nonpolar solvent molecules do not solvate ions well. The attractions of oppositely charged ions to each other are vastly greater than the weak attractions of the ions for the solvent.

Section:  3-10

MCAT:  1.3

GLO:  G2

 

 

74) Which compound is more soluble in water? Briefly explain your choice.

CH3OCH3 or CH3CH2OH

Answer:  CH3CH2OH is more soluble in water since it can donate a hydrogen bond to water and accept a hydrogen bond from water. CH3OCH3 can only accept a hydrogen bond from water; it has no hydrogen which can hydrogen bond to water.

Section:  3-10

MCAT:  2.5, 10.2, 14.1

GLO:  G2

 

75) Which compound is more soluble in water? Briefly explain your choice.

(CH3)2NH or CH3CH2CH3

Answer:  (CH3)2NH is more soluble in water since it can hydrogen bond with water. Alkanes are not capable of hydrogen bonding with water.

Section:  3-10

MCAT:  2.5, 19.4

 

76) Which intermolecular force is primarily responsible for the interactions among alkane molecules?

Answer:           Van der Waal’s or London forces

Section:  3-9

MCAT:  2.5

 

77) What is polarizability and how is it related to the size of an atom?

Answer:  Polarizability indicates the ease with which an electron cloud can be distorted. The larger the atom, the more loosely its nucleus holds the electrons in its outermost shell, and the more they can be distorted.

Section:  3-9

 

78) Arrange the following amines in order of increasing boiling point, lowest bp to highest bp: (CH3)2CHCH2CH2NH2, (CH3)2CHN(CH3)2, and (CH3)2CHCH2NHCH3.

Answer:  (CH3)2CHN(CH3)2 < (CH3)2CHCH2NHCH3 < (CH3)2CHCH2CH2NH2

Section:  3-9

MCAT:  19.4

GLO:  G2

79) The eclipsed and staggered forms of ethane are said to differ in

  1. A) molecular formula.
  2. B) configuration.
  3. C) conformation.
  4. D) constitution.
  5. E) structure.

Answer:  C

Section:  3-11

MCAT:  3.4

 

 

80) Which of the following is the staggered conformation for rotation about the C1—C2 bond in the following structure?

  1. A) I
  2. B) II
  3. C) III
  4. D) IV
  5. E) V

Answer:  A

Section:  3-11

MCAT:  3.4

 

81) Among the butane conformers, which occur at energy minima on a graph of potential energy versus dihedral angle?

  1. A) gauche only
  2. B) eclipsed and totally eclipsed
  3. C) gauche and anti
  4. D) eclipsed only
  5. E) anti only

Answer:  C

Section:  3-11

MCAT:  3.4

 

82) Which of the following best explains the relative stabilities of the eclipsed and staggered forms of ethane? The ________ form has the most ________ strain.

  1. A) eclipsed; steric
  2. B) eclipsed; torsional
  3. C) staggered; steric
  4. D) staggered; torsional

Answer:  B

Section:  3-11

MCAT:  3.4

 

83) Which of the following best explains the reason for the relative stabilities of the conformers shown?

  1. A) I has more torsional strain.
  2. B) I has more steric strain.
  3. C) II has more torsional strain.
  4. D) II has more steric strain.

Answer:  D

Section:  3-11

MCAT:  3.4

 

84) Which of the following statements about the conformers that result from rotation about the C2-C3 bond of butane is correct?

  1. A) The highest energy conformer is one in which methyl groups are eclipsed by hydrogens.
  2. B) The gauche conformer is an eclipsed one.
  3. C) Steric strain is absent in the eclipsed forms.
  4. D) Torsional strain is absent in the eclipsed forms.
  5. E) none of the above

Answer:  E

Section:  3-11

MCAT:  3.1

 

85) Draw the Newman projection that represents the most stable conformation of 3,3-dimethylhexane viewed along the C3-C4 bond.

Answer:

Section:  3-11

MCAT:  3.1, 3.4

GLO:  G2

 

86) Draw the Newman projection that represents the least stable conformation of 3,3-dimethylhexane viewed along the C3-C4 bond.

Answer:

Section:  3-11

MCAT:  3.1, 3.4

 

87) Draw the Newman structure for the most stable conformation of 1-bromopropane considering rotation about the C1-C2 bond.

Answer:

Section:  3-11

MCAT:  3.4, 6.1

 

88) Draw a Newman projection of the most stable conformation of 2-methylpropane.

Answer:

Section:  3-11

MCAT:  3.1, 3.4

 

89) Define the term conformation.

Answer:  Conformations are different arrangements of the same molecule formed by rotations about single bonds.

Section:  3-11

MCAT:  3.4

 

90) Use a sawhorse structure to depict the eclipsed conformer of ethane.

Answer:

Section:  3-11

MCAT:  3.1, 3.4

 

91) View a butane molecule along the C2-C3 bond and provide a Newman projection of the lowest energy conformer.

Answer:

Section:  3-11

MCAT:  3.1, 3.4

 

92) Provide a representation of the gauche conformer of butane.

Answer:

Section:  3-11

MCAT:  3.1, 3.4

 

93) Draw the Newman projection of the most stable conformation that results due to rotation about the C2-C3 bond in 2,3-dimethylbutane.

Answer:

Section:  3-11

MCAT:  3.1, 3.4

 

94) Identify the most stable conformation of butane.

  1. A) anti
  2. B) eclipsed
  3. C) gauche
  4. D) totally eclipsed
  5. E) adjacent

Answer:  A

Section:  3-11

MCAT:  3.1, 3.4

 

95) List the conformations in order of decreasing stability.

Answer:  6 > 3, 5 > 1, 4 > 2

Section:  3-11

MCAT:  3.4

 

96) Which of the following correctly ranks the cycloalkanes in order of increasing ring strain per methylene?

  1. A) cyclopropane < cyclobutane < cyclohexane < cycloheptane
  2. B) cyclohexane < cyclopentane < cyclobutane < cyclopropane
  3. C) cyclopentane < cyclobutane < cyclopentane < cyclopropane
  4. D) cyclopentane < cyclopropane < cyclobutane < cyclohexane
  5. E) cyclopropane < cyclopentane < cyclobutane < cyclohexane

Answer:  B

Section:  3-12

MCAT:  3.1, 3.3

 

97) Describe the source of angle strain and torsional strain present in cyclopropane.

Answer:  The angle strain arises from the compression of the ideal tetrahedral bond angle of 109.5° to 60°. The large torsional strain occurs since all C-H bonds on adjacent carbons are eclipsed.

Section:  3-12

MCAT:  3.1, 3.3

GLO:  G2

 

98) Which of the following correctly lists the conformations of cyclohexane in order of increasing energy?

  1. A) chair < boat < twist-boat < half-chair
  2. B) half-chair < boat < twist-boat < chair
  3. C) chair < twist-boat < half-chair < boat
  4. D) chair < twist-boat < boat < half-chair
  5. E) half-chair < twist-boat < boat < chair

Answer:  D

Section:  3-13

MCAT:  23.6

 

99) Which of the following is the most stable conformation of bromocyclohexane?

  1. A) I
  2. B) II
  3. C) III
  4. D) IV
  5. E) V

Answer:  C

Section:  3-14

MCAT:  23.6

 

100) In the boat conformation of cyclohexane, the “flagpole” hydrogens are located on

  1. A) the same carbon.
  2. B) adjacent carbons.
  3. C) C-1 and C-3.
  4. D) C-1 and C-4.
  5. E) none of the above.

Answer:  D

Section:  3-13

 

101) Which conformer is at a local energy minimum on the potential energy diagram in the chair-chair interconversion of cyclohexane?

  1. A) half-chair
  2. B) planar
  3. C) boat
  4. D) twist-boat
  5. E) fully eclipsed

Answer:  D

Section:  3-13

GLO:  G3

 

102) Draw the chair conformer of cyclohexane. Label the axial hydrogens (Ha) and the equatorial hydrogens (He).

Answer:

Section:  3-13

 

103) The Keq for the interconversion for the two chair forms of methylcyclohexane at 25 °C is 18. What % of the chair conformers feature an axial methyl group?

  1. A) 95
  2. B) 75
  3. C) 50
  4. D) 25
  5. E) 5

Answer:  E

Section:  3-14

GLO:  G2, G4

 

104) The equilibrium constant for the ring-flip of fluorocyclohexane is 1.5 at 25°C. Calculate the percentage of the axial conformer at the temperature.

Answer:  Keq =  = 1.5

% axial =  × 100%

=  × 100%

= 40%

Section:  3-14

GLO:  G2, G4

 

105) Which of the following describes the most stable conformation of trans-1-tert-butyl-3-methylcyclohexane?

  1. A) Both groups are equatorial.
  2. B) Both groups are axial.
  3. C) The tert-butyl group is equatorial and the methyl group is axial.
  4. D) The tert-butyl group is axial and the methyl group is equatorial.
  5. E) none of the above

Answer:  C

Section:  3-15

MCAT:  2.4, 3.5

 

106) Name the compound shown below.

  1. A) trans-1,2-dichlorocyclohexane
  2. B) cis-1,2-dichlorocyclohexane
  3. C) trans-1,3-dichlorocyclohexane
  4. D) cis-1,3-dichlorocyclohexane
  5. E) trans-1,4-dichlorocyclohexane

Answer:  D

Section:  3-15

MCAT:  3.5

 

107) Which of the following has two equatorial alkyl substituents in its most stable conformation?

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

Answer:  C

Section:  3-15

MCAT:  3.1, 3.3

GLO:  G2

108) Draw the most stable conformation of trans-1-tert-butyl-3-methylcyclohexane.

Answer:

or enantiomer

Section:  3-15

MCAT:  3.1, 3.3

GLO:  G2

 

109) Draw the most stable conformer of cis-1-isopropyl-2-methylcyclohexane.

Answer:

or enantiomer

Section:  3-15

MCAT:  3.5

GLO:  G2

 

110) Draw the most stable conformation of trans-1-isopropyl-2-methylcyclohexane.

Answer:

or enantiomer

Section:  3-15

MCAT:  3.5

GLO:  G2

 

111) Identify the number of secondary hydrogens in the following structure.

  1. A) 4
  2. B) 6
  3. C) 8
  4. D) 10
  5. E) 12

Answer:  C

Section:  3-1

112) Identify the compound where the groups are axial and equatorial.

  1. A) trans-1,4-dibromocyclohexane
  2. B) cis-1,4-dibromocyclohexane
  3. C) cis-1,3-dibromocyclohexane
  4. D) trans-1,2-dibromocyclohexane
  5. E) none of the above

Answer:  B

Section:  3-15

MCAT:  3.5, 6.1

 

113) Identify the least stable conformation for 1-tert-butyl-3-methylcyclohexane.

  1. A) tert-butyl is axial and the methyl is equatorial.
  2. B) tert-butyl is axial and the methyl is axial.
  3. C) tert-butyl is equatorial and the methyl is axial.
  4. D) tert-butyl is equatorial and the methyl is equatorial.
  5. E) All are equally stable.

Answer:  B

Section:  3-15

MCAT:  3.1, 3.5

GLO:  G2

 

114) Draw the most stable conformer of cis-1-ethyl-2-methylcyclohexane.

Answer:

Section:  3-15

MCAT:  3.1, 3.5

GLO:  G2

 

115) Draw the most stable conformer of trans-1-ethyl-2-methylcyclohexane.

Answer:

Section:  3-15

MCAT:  3.1, 3.5

GLO:  G2

 

116) Draw the most stable conformer of cis-1-ethyl-3-methylcyclohexane.

Answer:

Section:  3-15

MCAT:  3.1, 3.5

GLO:  G2

 

117) Draw the most stable conformer of trans-1-ethyl-3-methylcyclohexane.

Answer:

Section:  3-15

MCAT:  3.1, 3.5

GLO:  G2

 

118) Draw the most stable conformer of cis-1-ethyl-4-methylcyclohexane.

Answer:

Section:  3-15

MCAT:  3.1, 3.5

GLO:  G2

 

119) Draw the most stable conformer of trans-1-ethyl-4-methylcyclohexane.

Answer:

Section:  3-15

MCAT:  3.1, 3.5

GLO:  G2

 

120) What aspect of the fused ring systems present in cholesterol make it an ideal compound to lend rigidity to cell membranes?

Answer:  The trans-fused ring systems present in cholesterol are not able to undergo chair-chair interconversion (ring flip). This renders them a high degree of conformational rigidity.

Section:  3-16

MCAT:  3.5

GLO:  G2

 

121) Provide the chair structure of cis-decalin, two cis-fused six-membered rings.

Answer:

Section:  3-16

GLO:  G2

 

122) How many constitutional isomers are possible for C6H14?

  1. A) 4
  2. B) 5
  3. C) 6
  4. D) 7
  5. E) 8

Answer:  B

Section:  3-1

MCAT:  1.1, 3.2

 

123) If an acyclic alkane hydrocarbon contains n carbon atoms, how many hydrogen atoms must it also contain?

  1. A) n
  2. B) n + 2
  3. C) n – 2
  4. D) 2n
  5. E) 2n + 2

Answer:  E

Section:  3-1

 

124) Which of the following represent constitutional isomers?

  1. A) I and II
  2. B) I and III
  3. C) I and IV
  4. D) II and III
  5. E) I, II, III and IV

Answer:  E

Section:  3-0

MCAT:  2.4

 

125) Which of the following is true about the following compounds? You may choose more than one answer.

  1. A) These are identical compounds.
  2. B) These are constitutional isomers.
  3. C) These are conformational isomers.
  4. D) These are different compounds.
  5. E) There is no relationship.

Answer:  A, C

Section:  3-0

MCAT:  2.4

 

126) Acetone has higher boiling point than propane because

  1. A) double bond in acetone is hard to break.
  2. B) acetone has higher molecular weight.
  3. C) acetone exhibits dipole-dipole interactions which are stronger than van der Waal’s interactions in propane.
  4. D) acetone exhibit hydrogen bonding which is stronger than van der Waal’s interactions in propane.
  5. E) acetone has higher surface area.

Answer:  C

Section:  3-9

MCAT:  2.5

127) The parent chain in the following molecule is

  1. A) pentane.
  2. B) hexane.
  3. C) heptane.
  4. D) octane.
  5. E) nonane.

Answer:  C

Section:  3-11

MCAT:  3.1

 

128) What is the common name of the alkyl substituent present on C-2 of menthol shown below?

  1. A) isopropyl
  2. B) isobutyl
  3. C) sec-butyl
  4. D) tert-butyl
  5. E) iso-pentyl

Answer:  A

Section:  3-1

MCAT:  3.1

 

129) Name the following molecule.

Answer:  2-ethyl-2-methylhexan-1-ol

Section:  3-6, 3-11

MCAT:  10.1

 

130) The dihedral angle between the bromo and ethyl substituents present on the adjacent carbons of the following molecule is

  1. A) 0°
  2. B) 60°
  3. C) 90°
  4. D) 120°
  5. E) 180°

Answer:  E

Section:  3-11

 

131) Structure of commonly used anti-anxiety drug, valium is shown below. What are the strongest intermolecular interactions present between molecules?

  1. A) Van der Waals interactions
  2. B) dipole-dipole interactions
  3. C) hydrogen bonding
  4. D) covalent bonding
  5. E) ionic bonding

Answer:  B

Section:  3-9

MCAT:  2.5

 

132) Which of the following atoms has the highest polarizability?

  1. A) H
  2. B) O
  3. C) N
  4. D) C
  5. E) S

Answer:  E

Section:  3-9

GLO:  G2

133) Draw the Newman projection of the following molecule sighting down the indicated bond?

Answer:

Section:  3-11

MCAT:  3.4

 

134) In the chair conformation of cyclohexane, how many hydrogen atoms are eclipsed?

  1. A) 0
  2. B) 2
  3. C) 4
  4. D) 6
  5. E) 8

Answer:  A

Section:  3-15

 

 

135) Which of the following represents the ring flipped structure of the molecule below?

  1. A) I
  2. B) II
  3. C) III
  4. D) IV
  5. E) V

Answer:  D

Section:  3-15

MCAT:  5.1

136) How many axial hydrogens are present in this molecule?

  1. A) 2
  2. B) 3
  3. C) 4
  4. D) 5
  5. E) 6

Answer:  C

Section:  3-15

Organic Chemistry, 8e (Bruice)

Chapter 5   Alkenes: Structure, Nomenclature, and an Introduction to Reactivity – Thermodynamics and Kinetics

 

1) What is the molecular formula of the hydrocarbon that contains 5 carbon atoms, one ring, and one π bond?

Answer:  C5H8

Section:  5-1

GLO:  G2

 

2) What is the molecular formula of the hydrocarbon that contains 8 carbon atoms, one ring, and two π bonds?

Answer:  C8H12

Section:  5-1

GLO:  G2

 

3) Give the general formula for a cyclic alkene.

  1. A) CnH2n-4
  2. B) CnH2n-2
  3. C) CnH2n
  4. D) CnH2n+2

Answer:  B

Section:  5-1

 

4) Give the possibilities in structure for a compound with a formula of C6H10.

  1. A) no rings, no double bonds, no triple bonds
  2. B) one double bond, or one ring
  3. C) two rings, two double bonds, one double bond + one ring, or one triple bond
  4. D) three rings, three double bonds, two double bonds + one ring, one ring + two double bonds, one triple bond + one ring, or one double bond + one ring
  5. E) benzene

Answer:  C

Section:  5-1

 

5) Give the degree of unsaturation for benzene.

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

Answer:  D

Section:  5-1

 

6) β-Phellandrene is a hydrocarbon component of eucalyptus oil whose molecular formula is C10H16. A molecule of β-phellandrene contains 2 π-bonds. How many rings are in β-phellandrene?

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

Answer:  B

Section:  5-1

 

7) A hydrocarbon with molecular formula C20H34 has what degree of substitution?

  1. A) 2
  2. B) 3
  3. C) 4
  4. D) 5
  5. E) 6

Answer:  C

Section:  5-1

MCAT:  3.1

 

8) Muscalure, the sex attractant of the common housefly, is an acyclic alkene that contains 23 carbons. How many hydrogen atoms are in a molecule of muscalure?

Answer:  46

Section:  5-1

 

9) Provide an acceptable name for the following compound.

Answer:  2-ethyl-5,5-dimethyl-1-hexene or 2-ethyl-5,5-dimethylhex-1-ene

Section:  5-2

 

 

10) Provide an acceptable name for the following compound.

Answer:  1,6-dibromocyclohexene

Section:  5-2

MCAT:  3.1, 6.1

11) Name the structure.

  1. A) 2-ethyl-1-pentene
  2. B) 2-propyl-1-butene
  3. C) 3-methylenehexane
  4. D) 3-methyl-3-hexene
  5. E) ethyl propyl ethene

Answer:  A

Section:  5-2

MCAT:  7.1

 

12) Name the structure.

  1. A) 2-methyl-2,4-pentadiene
  2. B) 4-methyl-1,4-pentadiene
  3. C) 2-methylene-4-pentene
  4. D) 4-methylene-2-pentene
  5. E) 2-methyl-1,4-pentadiene

Answer:  E

Section:  5-2

MCAT:  7.1

 

 

13) Name the structure.

  1. A) 7-chloro-3-ethyl-4-methyl-3-heptene
  2. B) 1-chloro-5-ethyl-4-methyl-3-heptene
  3. C) 1-chloro-3-pentenyl-2-pentene
  4. D) cis-7-chloro-3-ethyl-4-methyl-3-heptene
  5. E) trans-7-chloro-3-ethyl-4-methyl-3-heptene

Answer:  A

Section:  5-2

MCAT:  6.1, 7.1

14) Name the structure.

  1. A) 4-chlorocyclohexene
  2. B) 1-chloro-3-cyclohexene
  3. C) 1-chloro-3-cycloheptene
  4. D) 4-chlorocycloheptane
  5. E) 4-chlorocycloheptene

Answer:  E

Section:  5-2

MCAT:  6.1, 7.1

 

15) Draw vinyl bromide.

Answer:  CH2CHBr

Section:  5-2

MCAT:  6.1, 7.1

 

16) Name the structure.

H2CCHCH2I

  1. A) vinyl iodide
  2. B) allyl iodide
  3. C) 1-iodo-2-propene
  4. D) iodomethylethene
  5. E) 2-iodo-1-propene

Answer:  B

Section:  5-2

MCAT:  6.1, 7.1

 

17) What is the common name for the following compound?

  1. A) t-butylene
  2. B) sec-butylene
  3. C) isobutylene
  4. D) butylene
  5. E) methylpropylene

Answer:  C

Section:  5-2

MCAT:  7.1

18) What is the IUPAC name for the following compound?

  1. A) 2-methyl-1-butene
  2. B) isopentene
  3. C) 2-methybutene
  4. D) 2-ethylpropene
  5. E) 3-methyl-3-butene

Answer:  A

Section:  5-2

MCAT:  7.1

 

19) What is the IUPAC name for the following compound?

  1. A) 5-methylcyclohexene
  2. B) 4-methylcyclohexene
  3. C) 1-methyl-3-cyclohexene
  4. D) 1-methyl-4-cyclohexene
  5. E) methylcyclohexene

Answer:  B

Section:  5-2

MCAT:  7.1

 

 

20) Which of the following is vinyl chloride?

  1. A) CH3CH2Cl
  2. B) CH2CHCH2Cl
  3. C) CH2CHCl
  4. D)
  5. E)

Answer:  C

Section:  5-2

MCAT:  6.1, 7.1

21) Which of the following is an allylic alcohol?

  1. A) CH2CHCH2OCH3
  2. B) CH2CHCH2CH3
  3. C) HOCHCHCH2CH3
  4. D) CH3CHCHCH2OH
  5. E) CH2CHCH2CH2OH

Answer:  D

Section:  5-2

MCAT:  7.1, 10.1

 

22) Provide the IUPAC name for the alkene shown below.

Answer:  (E)-3,4-dimethyl-3-heptene

Section:  5-2

MCAT:  7.1, 7.3

 

 

23) Provide the proper IUPAC name for the alkene shown below.

Answer:  6-bromo-1-methylcyclohexene

Section:  5-2

MCAT:  6.1, 7.1

24) Draw and name the six alkenes which have the molecular formula C5H10.

Answer:

Section:  5-2

MCAT:  1.1, 3.2

 

25) Provide the systematic name of the alkene below.

Answer:  2-ethyl-1-hexene

Section:  5-2

MCAT:  7.1

 

 

26) Provide an acceptable name of the compound below.

Answer:  5-isobutyl-1-methylcyclopentene

Section:  5-2

MCAT:  7.1

 

27) Which of the following statements about ethene, C2H4, is incorrect?

  1. A) The H-C-H bond angles are approximately 109.5°.
  2. B) All of the hydrogen atoms are in the same plane.
  3. C) There is a total of five sigma bonds.
  4. D) The carbon atoms are sp2
  5. E) The H-C-H bond angles are approximately 120°.

Answer:  A

Section:  5-3

MCAT:  2.2, 7.5

28) Which of the following statements about propene, CH3CHCH2, is correct?

  1. A) All nine atoms lie in the same plane.
  2. B) The compound has a cis and trans isomer.
  3. C) It generally acts as a Lewis acid.
  4. D) There is a total of eight sigma bonds.
  5. E) All the carbon atoms are sp2

Answer:  D

Section:  5-3

MCAT:  7.5

 

29) Draw the structure of propyl vinyl ether.

Answer:

Section:  5-2

MCAT:  7.1, 14.1

 

30) Give the hybridization, shape, and bond angle for a carbon in ethene.

Answer:  sp2, trigonal planar, 120°

Section:  5-3

 

 

31) Name the structure.

  1. A) cis-3-ethyl-4-hydroxymethyl-hex-3-en-1-yne
  2. B) cis-2,3-diethylpent-2-en-4-yn-1-ol
  3. C) trans-2,3-diethylpent-2-en-4-yn-1-ol
  4. D) cis-3,4-diethylpent-3-en-1-yn-5-ol
  5. E) trans-3,4-diethylpent-3-en-1-yn-5-ol

Answer:  C

Section:  5-2

MCAT:  7.1, 7.3, 9.1

 

32) How many carbons are in the planar double-bond system of 3-methylcyclopentene?

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

Answer:  C

Section:  5-3

MCAT:  7.1

33) Name the structure.

  1. A) cis-4,5-dimethyl-4-hepten-1-ol
  2. B) trans-3,4-dimethyl-3-hepten-7-ol
  3. C) cis-3,4-dimethyl-3-hepten-7-ol
  4. D) trans-4,5-dimethyl-4-hepten-1-ol
  5. E) trans-4,5-dimethyl-4-heptenol

Answer:  D

Section:  5-2

MCAT:  7.1, 7.3, 10.1

 

 

34) Name the structure.

  1. A) (Z)-4,5-dimethyl-4-hepten-1-ol
  2. B) (E)-4,5-dimethyl-4-hepten-1-ol
  3. C) (E)-3,4-dimethyl-3-hepten-7-ol
  4. D) (Z)-3,4-dimethyl-3-hepten-7-ol
  5. E) (E)-4,5-dimethyl-4-heptenol

Answer:  B

Section:  5-2

MCAT:  7.1, 7.3, 10.1

 

35) Name the structure.

  1. A) (Z)-3-ethyl-2-hydroxymethyl-2-penten-4-ynal
  2. B) (E)-3-ethyl-2-hydroxymethyl-2-penten-4-ynal
  3. C) (Z)-3-ethyl-5-hydroxymethyl-3-penten-1-ynal
  4. D) (E)-3-ethyl-5-hydroxymethyl-3-penten-1-ynal
  5. E) 3-ethyl-5-hydroxymethyl-3-penten-1-ynal

Answer:  A

Section:  5-2

MCAT:  7.1, 9.1, 18.1

 

36) Name the structure.

  1. A) (2E,4E)-7-chloro-2,4-heptadiene
  2. B) (2Z,4E)-7-chloro-2,4-heptadiene
  3. C) (2Z,4Z)-7-chloro-2,4-heptadiene
  4. D) (2E,4Z)-7-chloro-2,4-heptadiene
  5. E) 7-chloro-2,4-heptadiene

Answer:  D

Section:  5-2

MCAT:  6.1, 7.1

 

37) Draw (E)-2-methyl-3-hexen-1-ol.

Answer:

Section:  5-2

MCAT:  7.1, 10.1

 

38) Provide the systematic name of the compound shown below. Make sure to include the E or Z designator if necessary.

Answer:  (E)-4-ethyl-3-nonene

Section:  5-2

MCAT:  7.1, 7.3

 

39) Provide the systematic name of the compound shown below. Make sure to include the E or Z designator if necessary.

Answer:  (Z)-4-fluoro-3-heptene

Section:  5-2

 

40) Draw the structure of (Z)-1-chloro-2-methyl-2-butene.

Answer:

Section:  5-2

MCAT:  6.1, 7.1, 7.3

 

41) Which of the following is capable of exhibiting cis-trans isomerism?

  1. A) 1-butene
  2. B) 1-pentene
  3. C) cyclohexene
  4. D) ethene
  5. E) 2-butene

Answer:  E

Section:  5-2

MCAT:  7.5

 

42) Draw all the possible constitutional isomers of C4H8.

Answer:

Section:  5-2

MCAT:  1.1, 3.2

 

43) Draw the structure of two alkenes with molecular formula C4H8 that do not exhibit cis-trans isomerism.

Answer:

Section:  5-2

MCAT:  3.2

GLO:  G2

 

44) Which of the following best describes the geometry about the carbon-carbon double bond in the alkene below?

  1. A) E
  2. B) Z
  3. C) neither E nor Z

Answer:  C

Section:  4-2

MCAT:  7.3

 

45) Assign the E or Z configurational label to the following molecule:

Answer:  The molecule has a Z configuration based on the priority rule established by Cahn-Ingold-Prelog.

Section:  4-2

MCAT:  7.3

 

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

Answer:

Section:  5-2

MCAT:  7.3

 

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

Answer:

Section:  5-2

MCAT:  7.3

 

48) Which of the following is not an electrophile?

  1. A) H+
  2. B) BF3
  3. C) +NO2
  4. D) Fe+3
  5. E) CH2CH2

Answer:  E

Section:  5-5

MCAT:  1.4

 

49) Which of the following is not a nucleophile?

  1. A) FeBr3
  2. B) Br-
  3. C) NH3
  4. D)
  5. E) CH3OCH3

Answer:  A

Section:  5-5

MCAT:  1.4

 

50) Draw the curved arrows to show how CH3CH=CHCH3 reacts with HBr to form a carbocation.

Answer:

Section:  5-5

MCAT:  1.4

 

51) Give the mechanism for the following reaction.

Answer:

Section:  5-5

MCAT:  1.4

 

52) Identify the nucleophiles and electrophiles.

-OH, BH3, H2O, +CH3, NH3, Br-

Answer:  nucleophiles: -OH, H2O, NH3, Br-

electrophiles: BH3, +CH3

Section:  5-5

MCAT:  1.4

53) Calculate the enthalpy for the following reaction.

H-Cl, 103 kcal/mole

CH3CH2-H, 101 kcal/mole

CH3CH2-Cl, 85 kcal/mole

Answer:  -21 kcal/mole

Section:  5-8

GLO:  G4

 

54) What is the value of ΔH in kcal/mole for the reaction shown?

 

(CH3)3C—H + Cl—Cl → (CH3)3C—Cl + H—Cl

 

Bond energies are:      (CH3)3C—H = 91 kcal/mole

(CH3)3C—Cl = 78.5 kcal/mole

Cl—Cl = 58 kcal/mole

H—Cl = 103 kcal/mole

  1. A) +32.5
  2. B) -57.5
  3. C) -32.5
  4. D) +57.5
  5. E) -8.5

Answer:  C

Section:  5-8

GLO:  G4

 

 

55) How many transition states are present in the following reaction diagram?

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

Answer:  D

Section:  5-12

GLO:  G3, G4

56) An increase in which of the following results in a decrease in the rate of the chemical reaction?

  1. A) temperature
  2. B) concentration
  3. C) collision frequency
  4. D) energy of activation
  5. E) fraction of collisions with proper orientation

Answer:  D

Section:  5-11

GLO:  G2

 

57) An increase in which of the following will occur if the reaction temperature is increased?

  1. Energy of activation
  2. Collision frequency

III. Fraction of collisions with sufficient energy

  1. A) I and II
  2. B) I and III
  3. C) II and III
  4. D) I, II, and III
  5. E) I

Answer:  C

Section:  5-11

GLO:  G2

 

 

58) What is the activation energy for the reaction B → A in the following diagram?

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

Answer:  E

Section:  5-10

 

59) Which of the following contributes to make ΔG° more negative?

  1. A) use of a catalyst
  2. B) a more positive ΔH°
  3. C) a more positive ΔS°
  4. D) a larger rate constant
  5. E) none of the above

Answer:  C

Section:  5-10

60) Which of the following correctly describes intermediates and/or transition states?

  1. A) Transition states occur at minima on reaction coordinate diagrams.
  2. B) Both transition states and intermediates occur at maxima on reaction coordinate diagrams.
  3. C) An intermediate is always produced after the rate-determining step of a reaction mechanism.
  4. D) Transition states have partially formed bonds whereas intermediates have fully formed bonds.
  5. E) none of the above

Answer:  D

Section:  5-12

 

61) Which of the following correctly describes the reaction shown?

  1. A) ΔH° >0 and ΔS° >0
  2. B) ΔH° >0 and ΔS <0
  3. C) ΔH° <0 and ΔS >0
  4. D) ΔH° <0 and ΔS <0
  5. E) ΔH° = ΔS = 0

Answer:  D

Section:  5-6

GLO:  G3

 

62) Under what conditions is ΔG° equal to ΔH° for a chemical reaction?

Answer:  Since ΔG° = ΔH° – TΔS°, then ΔG° is equal to ΔH° when TΔS° is zero.

Section:  5-6

GLO:  G2

 

63) Consider the conversion of C to D via a one-step mechanism. The activation energy of this conversion is 3 kcal/mol. The energy difference between D and the transition state of the reaction is 7 kcal/mol. Estimate ΔH° for the reaction C → D.

Answer:  4 kcal/mol

Section:  5-6

GLO:  G4

64) Consider the one-step conversion of F to G. Given that the reaction is endergonic by 5 kcal/mol and that the energy difference between G and the transition state for the process is 15 kcal/mol, sketch a reaction-energy profile for this reaction. Make sure to show how the given energy differences are consistent with your sketch.

Answer:

Section:  5-6

GLO:  G2, G3

 

 

65) The ΔG° for the conversion of “axial” isopropylcyclohexane to “equatorial” isopropylcyclohexane at 298K is -2.1 kcal/mol. Calculate the percentage of isopropylcyclohexane molecules that have the isopropyl substituent in the axial position at this temperature.

[R = 1.987 × 10-3 kcal mol-1K-1]

Answer:  ΔG° = -RTlnK

-2.1 kcal/mol = -(1.987 × 10-3 kcal mol-1 K-1)(298K)lnK

lnK =

K =  = 34.7

% axial =  × 100%

=  × 100%

= 2.8%

Section:  5-6

66) Based on the following energy diagram, which compound, A or C, is formed faster from B? Which is more stable, A or C? Explain.

Answer:  A is formed faster since the pathway for its formation has the smaller activation energy. C is more stable than A because it has a lower energy.

Section:  5-6, 5-10

GLO:  G3

 

67) Consider the single step interconversion of A and B shown below. How is the equilibrium constant K related to the rate constants k1 and k -1 and to the amounts of A and B present at equilibrium?

Answer:  K =  =

Section:  5-11

GLO:  G4

 

68) Why do reactions tend to proceed at a faster rate as T increases?

Answer:  The number of molecular collisions that possesses sufficient energy to overcome the barrier to reaction increases.

Section:  5-11

 

69) The Arrhenius equation models how the rate constant k

  1. A) increases as both Eaand T increase.
  2. B) increases most when Eaincreases and T decreases.
  3. C) increases most when Eadecreases and T increases.
  4. D) increases as both Eaand T decrease.
  5. E) increases as reactant concentrations increase.

Answer:  C

Section:  5-11

70) Which of the following correctly describes the reaction whose reaction coordinate diagram is shown?

  1. A) endergonic with no transition state
  2. B) exergonic with no transition state
  3. C) endergonic with a transition state
  4. D) exergonic with a transition state
  5. E) endergonic with an intermediate

Answer:  D

Section:  5-6

GLO:  G3

 

71) Given an activation energy of 15 kcal/mol, use the Arrhenius equation to estimate how much faster the reaction will occur if the temperature is increased from 100°C to 120°C. R = 1.987 cal/mol ∙ K.

Answer:  The reaction will occur about 2.8 times faster.

Section:  5-11

GLO:  G4

 

 

72) What is the free energy of activation of a one-step reaction? How is it qualitatively related to the rate constant of the reaction?

Answer:  The free energy of activation of a one-step reaction is the difference in free energy between the transition state and the reactants. As the free energy of activation increases, the rate constant decreases.

Section:  5-10

73) Consider the reaction coordinate diagram shown. Which step has the greatest activation energy?

  1. A) A going to C
  2. B) C going to E
  3. C) E going to G
  4. D) E going to C
  5. E) C going to A

Answer:  D

Section:  5-12

GLO:  G3

 

 

74) Consider the reaction coordinate diagram shown. Which letters designate intermediates?

Answer:  C and E

Section:  5-12

GLO:  G3

75) Consider the reaction coordinate diagram shown. Which step has the greatest rate constant in the forward direction?

Answer:  Step 3 (E going to G)

Section:  5-12

GLO:  G3

 

 

76) Consider the reaction coordinate diagram shown. What is the rate-determining step in the conversion of A to G?

Answer:  Step 2 ( C going to E)

Section:  5-12

GLO:  G3

77) How many degrees of unsaturation are present in a molecule with formula C10H16?

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

Answer:  C

Section:  5-1

 

78) Linalool is a major compound present in the essential oil of coriander. How many degrees of unsaturation are present in this molecule?

  1. A) 2
  2. B) 3
  3. C) 4
  4. D) 5
  5. E) 6

Answer:  A

Section:  5-1

 

 

79) How many degrees of unsaturation are present in this molecule?

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

Answer:  D

Section:  5-1

 

80) Provide the proper IUPAC name of the following compound

Answer:  (Z)-3-methylhex-3-ene

Section:  5-2

MCAT:  7.3

81) Using curved arrows show the movement of electrons in the following reaction.

Answer:

Section:  5-5

MCAT:  1.4

 

 

82) Indicate the electrophile and nucleophile in the chemical reaction?

Answer:

Section:  5-5

MCAT:  1.4

 

83) A carbocation is

  1. A) a carbon with a negative charge
  2. B) a carbon with a positive charge
  3. C) a carbon with an unpaired electron
  4. D) a carbon with complete octet
  5. E) a carbon with five hydrogens

Answer:  B

Section:  5-5

MCAT:  4.2

 

84) The rate determining step of a reaction is the

  1. A) slowest step and thus, has highest energy barrier
  2. B) slowest step and thus, has lowest energy barrier
  3. C) fastest step and thus, has highest energy barrier
  4. D) fastest step and thus, has lowest energy barrier
  5. E) none of the above

Answer:  A

Section:  5-12

Organic Chemistry, 8e (Bruice)

Chapter 9   Substitution and Elimination Reactions of Alkyl Halides

 

1) What is the nucleophile in the reaction shown below?

 

  1. A) I
  2. B) II
  3. C) III
  4. D) IV
  5. E) V

Answer:  B

Section:  9-3

MCAT:  1.4, 6.1

 

2) Which of the following is not a nucleophile?

  1. A) CH3NH2
  2. B) PH3
  3. C) +CH3

D)

 

E)

 

Answer:  C

Section:  9-2

MCAT:  1.4

 

3) Which of the following best describes the carbon-chlorine bond of an alkyl chloride?

  1. A) nonpolar; no dipole
  2. B) polar; δ+ at carbon and δ- at chlorine
  3. C) polar; δ- at carbon and δ+ at chlorine
  4. D) ionic
  5. E) none of the above

Answer:  B

Section:  9-0

MCAT:  1.5, 6.1

 

4) Which of the following is not normally considered to be a nucleophile?

  1. A) NH3
  2. B) NH2CH3
  3. C) HC C:-
  4. D) CH3CH2+

Answer:  D

Section:  9-2

MCAT:  1.4

 

5) Give the mechanism including the transition state.

 

Answer:

 

Section:  9-1

MCAT:  6.2

 

6) Give the mechanism including the transition state.

 

Answer:

 

Section:  9-1

MCAT:  6.2

 

7) Identify the alkyl halide that reacts the fastest in a SN2 reaction.

  1. A) 2-chloro-2-methylpropane
  2. B) 2-chlorobutane
  3. C) 1-chlorobutane
  4. D) chloromethane

Answer:  D

Section:  9-1

MCAT:  6.3

 

8) Identify the alkyl halide that reacts the fastest in an SN2 reaction.

  1. A) 1-chloropropane
  2. B) 1-bromopropane
  3. C) 1-fluoropropane
  4. D) 1-iodopropane

Answer:  D

Section:  9-1

MCAT:  6.3

 

 

9) Identify the strongest nucleophile in an SN2 reaction.

  1. A) isopropoxide ion
  2. B) tert-butoxide ion
  3. C) ethoxide ion
  4. D) tert-pentoxide ion

Answer:  C

Section:  9-2

MCAT:  6.3

10) Which of the following are the substitution products of the reaction shown below?

CH3CH2Br + -OH → ?

  1. A) CH3CH2BrH+ + O-
  2. B) HOCH2CH2Br
  3. C) CH3CH2OH + Br-
  4. D) CH2 CH2 + Br- + H2O
  5. E) CH2 CHBr + H2O

Answer:  C

Section:  9-1

MCAT:  6.1, 6.2

 

 

11) Which of the following alkyl halides gives the slowest SN2 reaction?

  1. A) CH3CH2Cl

B)

 

C)

 

D)

 

E)

 

Answer:  C

Section:  9-1

MCAT:  6.3

 

 

12) Assuming no other changes, what is the effect of doubling only the concentration of the alkyl halide in the above SN2 reaction?

  1. A) no change
  2. B) doubles the rate
  3. C) triples the rate
  4. D) quadruples the rate
  5. E) rate is halved

Answer:  B

Section:  9-1

MCAT:  6.3

 

 

13) Assuming no other changes, what is the effect of doubling both the alkyl halide and the nucleophile concentrations in the above reaction?

  1. A) no change
  2. B) doubles the rate
  3. C) triples the rate
  4. D) quadruples the rate
  5. E) rate is halved

Answer:  D

Section:  9-1

MCAT:  6.3

 

14) Which of the following SN2 reactions is the fastest?

A)

 

  1. B) CH3CH2CH2I + HO- → CH3CH2CH2OH + I-

C)

 

  1. D) CH3CH2CH3Br + HO- → CH3CH2CH3OH + Br-
  2. E) CH3CH2CH2I + H2O → CH3CH2CH2OH + HI

Answer:  B

Section:  9-1, 9-2

MCAT:  6.3

15) Which of the following SN2 reactions is the slowest?

  1. A) CH3CH2CH3Br + HO- → CH3CH2CH3OH + Br-
  2. B) CH3CH2CH2Cl + HO- → CH3CH2CH2OH + Cl-
  3. C) CH3CH2CH2I + HO- → CH3CH2CH2OH + I-
  4. D) CH3CH2CH3F + HO- → CH3CH2CH2OH + F-

E)

 

Answer:  E

Section:  9-1, 9-2

MCAT:  6.3

 

 

16) Which of the following compounds will undergo an SN2 reaction most readily?

  1. A) (CH3)3CCH2I
  2. B) (CH3)3CCl
  3. C) (CH3)2CHI
  4. D) (CH3)2CHCH2CH2CH2Cl
  5. E) (CH3)2CHCH2CH2CH2I

Answer:  E

Section:  9-1, 9-2

MCAT:  6.3

 

17) Which of the following is a secondary alkyl halide?

  1. A) CH3Br
  2. B) (CH3)3CBr
  3. C) (CH3)2CHBr
  4. D) (CH3)2CHCH2Br

Answer:  C

Section:  9-1, 9-2

MCAT:  6.1

 

18) Which of the following SN2 reactions is the fastest?

  1. A) CH3CH2CH2CH2Br + OH- → CH3CH2CH2CH2OH + Br-
  2. B) CH3CH2CH2CH2Br + H2O → CH3CH2CH2CH2OH + HBr
  3. C) CH3CH2CHBrCH3 + OH- → CH3CH2CHOHCH3 + Br-
  4. D) CH3CH2CHBrCH3 + H2O → CH3CH2CHOHCH3 + HBr

Answer:  A

Section:  9-1, 9-2

MCAT:  6.3

19) Which of the following SN2 reactions is the slowest?

  1. A) CH3CH2CHBrCH3 + OH- → CH3CH2CHOHCH3 + Br-
  2. B) CH3CH2CHBrCH3 + H2O → CH3CH2CHOHCH3 + HBr
  3. C) CH3CH2CH2CH2Br + OH- → CH3CH2CH2CH2OH + Br-
  4. D) CH3CH2CH2CH2Br + H2O → CH3CH2CH2CH2OH + HBr

Answer:  B

Section:  9-1, 9-2

MCAT:  6.3

 

 

20) Which of the following does not provide evidence that there are two different mechanisms for nucleophilic substitution?

  1. A) reaction products when CH3I is used as the substrate
  2. B) reaction products when (CH3)3CCH2I is used as substrate
  3. C) the stereochemistry of nucleophilic substitutions
  4. D) the effect of nucleophile concentration on rate

Answer:  A

Section:  9-1

MCAT:  6.3

GLO:  G1, G2

 

21) What product results from the SN2 reaction between (R)-2-chloropentane and hydroxide?

  1. A) (R)-2-pentanol
  2. B) (S)-2-pentanol
  3. C) racemic pentanol
  4. D) 1-pentanol
  5. E) 3-pentanol

Answer:  B

Section:  9-1

MCAT:  5.3, 6.1, 6.2

 

22) Provide a detailed, stepwise mechanism for the reaction below.

(CH3)2CHCH2CH2CH2I + CN- → (CH3)2CHCH2CH2CH2CN + I-

Answer:

 

Section:  9-2

MCAT:  1.4

 

23) Do all primary alkyl iodides undergo SN2 reactions with sodium cyanide in DMSO at identical rates? Explain.

Answer:  No. All primary iodides are not equally accessible to attack by the CN-. Steric hindrance varies among primary iodides.

Section:  9-1

GLO:  G2, G8

24) Provide the structure of the major organic product which results when (S)-2-iodopentane is treated with KCN in DMF.

Answer:

 

Section:  9-1

 

 

25) Provide the structure of the major organic product in the following reaction.

 

Answer:

 

Section:  9-1

 

26) Provide the structure of the major organic product in the following reaction.

(CH3)3N + CH3CH2CH2I →

Answer:  [(CH3)3NCH2CH2CH3]+ I-

Section:  9-1

 

27) Provide the major organic product(s) in the reaction below.

 

Answer:

 

Section:  9-1

MCAT:  6.2

28) Provide the major organic product(s) in the reaction below.

 

Answer:

 

Section:  9-1

MCAT:  6.2

 

 

29) Provide the major organic product(s) in the reaction below.

 

Answer:

 

Section:  9-1

MCAT:  6.2

 

30) Draw and describe the transition state in the SN2 reaction between CH3I and CH3CH2O-Na+.

Answer:  In this transition state the oxygen-carbon bond is partially formed and the carbon-iodine bond is partially broken. There is essentially a trigonyl bipyramidal electron geometry around the carbon being attacked by the ethoxide, and the O-C-I angle is 180°. Both the oxygen and iodine atoms possess a partial negative charge.

 

Section:  9-1

GLO:  G7

31) In an SN2 reaction why does the nucleophile attack the carbon on the side opposite the leaving group?

Answer:  Back side attack occurs because the orbital of the nucleophile that contains its nonbonding electrons interacts with the empty σ* MO associated with the carbon-halogen bond. This orbital has its larger lobe on the side of the carbon directed away from the carbon-halogen bond, thus the nucleophile can achieve the best overlap with this lobe.

Section:  9-1

MCAT:  6.2

GLO:  G8

 

 

32) Provide the structure of the major organic product of the following reaction.

 

Answer:

 

Section:  9-1

 

33) Provide the structure of the major organic product of the following reaction.

 

Answer:

 

Section:  9-1

MCAT:  6.2

 

34) Provide the structure of the major organic product of the following reaction.

 

Answer:

Section:  9-1

 

35) Which of the following is the strongest nucleophile in an aqueous solution?

  1. A) HO-
  2. B) F-
  3. C) Cl-
  4. D) Br-
  5. E) I-

Answer:  E

Section:  9-2

GLO:  G2

 

36) Which of the following is the best leaving group?

  1. A) HO-
  2. B) F-
  3. C) Cl-
  4. D) Br-
  5. E) I-

Answer:  E

Section:  9-2

MCAT:  6.1

 

37) Which of the following species is most reactive in an SN2 reaction?

  1. A) CH3CH2—Cl
  2. B) CH3CH2—Br
  3. C) CH3CH2—I
  4. D) CH3CH2—F
  5. E) CH3CH2—OH

Answer:  C

Section:  9-2

MCAT:  6.1

 

38) Which of the following species is the least nucleophilic?

  1. A) (CH3)3CO-
  2. B) H2O
  3. C) (CH3)3N
  4. D) BF3
  5. E) CN-

Answer:  D

Section:  9-2

GLO:  G2

 

39) Which of the following is the best nucleophile in water?

  1. A) I-
  2. B) CH3SCH3
  3. C) CH3OCH3
  4. D) Cl-

Answer:  A

Section:  9-2

 

40) Which of the following statements concerning SN2 reactions of alkyl halides is not correct?

  1. A) The rate of reaction depends on the concentration of the nucleophile.
  2. B) The rate of reaction depends on the concentration of the alkyl halide.
  3. C) The rate of reaction of a particular alkyl bromide depends on the steric accessibility of the carbon of the C-Br bond.
  4. D) All alkyl iodides react more rapidly than all alkyl chlorides.
  5. E) The rate of reaction depends on the relative nucleophilicity of the nucleophile.

Answer:  D

Section:  9-1, 9-2

MCAT:  6.3

 

41) Which of the following correctly describes the relative nucleophilicities of methoxide and tert-butoxide?

  1. A) These alkoxides have essentially the same nucleophilicities since the negative charge in both is localized on an oxygen atom.
  2. B) Methoxide is more nucleophilic because the nucleophilicity of tert-butoxide is diminished by steric effects.
  3. C) tert-Butoxide is more nucleophilic because it contains three methyl groups which increase the charge on its oxygen by donating electron density.
  4. D) tert-Butoxide is more nucleophilic because it is more basic.
  5. E) none of the above

Answer:  B

Section:  9-2

GLO:  G2

 

42) Which of the following bromides reacts readily via an SN2 reaction with NaN3?

  1. A) C6H5Br
  2. B) CH3CH2CH=CHBr
  3. C) (C6H5)3CBr
  4. D) (CH3)3CCH2CH2CH2Br
  5. E) 1-bromo-1-methylcyclohexane

Answer:  D

Section:  9-1, 9-13

 

43) Which halide reacts most rapidly via an SN2 mechanism?

  1. A) (CH3)CCH2CH2F
  2. B) (CH3)CCH2CH2Cl
  3. C) (CH3)CCH2CH2Br
  4. D) (CH3)CCH2CH2I
  5. E) All primary halides react at the same rate in SN2.

Answer:  D

Section:  9-2

MCAT:  6.1

 

44) Which halide reacts most rapidly via an SN2 mechanism?

A)

 

B)

 

C)

 

D)

 

E)

 

Answer:  E

Section:  9-1

MCAT:  6.3

 

 

45) Which halide reacts most rapidly via an SN2 mechanism?

A)

 

B)

 

C)

 

D)

 

E)

 

Answer:  E

Section:  9-2

MCAT:  6.3

 

46) Rank the species below in order of increasing nucleophilicity in protic solvents:

CH3CO2- , CH3S- , HO- , H2O.

Answer:  H2O < CH3CO2- < HO- < CH3S-

Section:  9-2

GLO:  G2

 

 

47) In each of the pairs below, which is the best nucleophile in alcoholic solvents?

  1. CH3S- or CH3O-
  2. (CH3)2NH or (CH3)3N
  3. Cl- or F-
  4. SCN- or OCN-

Answer:  a. CH3S-

  1. (CH3)2NH
  2. Cl-
  3. SCN-

Section:  9-2

 

48) Why, in a polar protic solvent, is iodide a better nucleophile than fluoride?

Answer:  In addition to iodide being more polarizable due to its larger size, the fluoride ion is more highly solvated which retards its ability to function as a nucleophile.

Section:  9-2

GLO:  G8

49) Which of the following iodides undergoes SN2 reaction with cyanide (CN-) the fastest?

  1. A) 1-iodo-3-methylpentane
  2. B) 2-iodopentane
  3. C) 2-iodo-2-methylpentane
  4. D) 3-iodopentane
  5. E) 1-iodo-2,2-dimethylpentane

Answer:  A

Section:  9-1

MCAT:  6.1, 6.2

 

50) Provide the major organic product(s) of the reaction shown.

 

Answer:

 

Section:  9-1

MCAT:  6.1

 

 

51) Provide the major organic product(s) of the reaction shown.

 

Answer:

 

Section:  9-1

MCAT:  6.1

 

52) A student attempted to prepare 1-chlorobutane by treating 1-butanol with NaCl in acetone. Was the student successful? Explain.

Answer:  The student was unsuccessful. The reaction would require chloride to displace hydroxide. Since hydroxide is a much stronger base, and therefore a much poorer leaving group, the reaction does not occur.

Section:  9-2

GLO:  G2, G7

53) Rank the species below in order of leaving group capabilities in SN2 reactions (worst leaving group to best):

CH3O-, H2O, C6H5SO3-, H2N-.

Answer:  H2N- < CH3O- < C6H5SO3- < H2O

Section:  9-2

 

 

54) Give the mechanism.

 

Answer:

 

Section:  9-3

GLO:  G2

 

 

55) Give the mechanism of the reaction shown below.

 

Answer:

 

Section:  9-3

GLO:  G2

 

56) Identify the alkyl halide that reacts the fastest in an SN1 reaction.

  1. A) 2-chloro-2-methylpropane
  2. B) 2-chlorobutane
  3. C) 1-chlorobutane
  4. D) chloromethane

Answer:  A

Section:  9-3

MCAT:  6.1

 

57) Identify the alkyl halide that reacts the fastest in an SN1 reaction.

  1. A) 2-chloropropane
  2. B) 2-bromopropane
  3. C) 2-fluoropropane
  4. D) 2-iodopropane

Answer:  D

Section:  9-4

MCAT:  6.1

 

 

 

58) Assuming no other changes, what is the effect of doubling only the concentration of the alkyl halide in the above SN1 reaction?

  1. A) no change
  2. B) doubles the rate
  3. C) triples the rate
  4. D) quadruples the rate
  5. E) rate is halved

Answer:  B

Section:  9-3

 

59) Assuming no other changes, what is the effect of doubling only the concentration of the nucleophile in the above reaction?

  1. A) no change
  2. B) doubles the rate
  3. C) triples the rate
  4. D) quadruples the rate
  5. E) rate is halved

Answer:  A

Section:  9-3

 

60) Assuming no other changes, what is the effect of doubling both the concentration of the alkyl halide and the nucleophile in the above reaction?

  1. A) no change
  2. B) doubles the rate
  3. C) triples the rate
  4. D) quadruples the rate
  5. E) rate is halved

Answer:  B

Section:  9-3

GLO:  G2

 

61) Which of the following alkyl halides gives the fastest SN1 reaction?

  1. A) CH3CH2CH2Br

B)

 

C)

 

  1. D) CH3CH2CH2I
  2. E) CH3CH2CH2Cl

Answer:  C

Section:  9-3

MCAT:  6.1

 

62) Which of the following alkyl halides gives the fastest SN1 reaction?

A)

 

B)

 

C)

 

D)

 

E)

 

Answer:  C

Section:  9-3, 9-4

MCAT:  6.1

 

63) Which of the following factors has no effect on the rate of SN1 reactions?

  1. A) the nature of the alkyl halide
  2. B) the nature of the leaving group
  3. C) the concentration of the alkyl halide
  4. D) the concentration of the nucleophile
  5. E) the value of the rate constant

Answer:  D

Section:  9-3

MCAT:  6.3

 

64) Which of the following carbocations is the most stable?

A)

 

B)

 

C)

 

D)

 

E)

 

Answer:  C

Section:  9-7

MCAT:  4.2

 

65) Which of the following is the rate law for SN1 mechanisms?

  1. A) Rate = k[Alkyl Halide] [Nucleophile]
  2. B) Rate = k[Nucleophile]
  3. C) Rate = k[Alkyl Halide]
  4. D) Rate = k[Alkyl Halide] [Nucleophile] + k2[Alkyl Halide]
  5. E) Rate = k1[Alkyl Halide] + k2[Nucleophile]

Answer:  C

Section:  9-3

MCAT:  6.3

 

66) Which of the following carbocations is the least stable?

 

  1. A) I
  2. B) II
  3. C) III
  4. D) IV
  5. E) V

Answer:  A

Section:  9-7

MCAT:  4.2

 

67) Which of the compounds below undergoes solvolysis in aqueous ethanol most rapidly?

  1. A) cyclohexyl bromide
  2. B) methyl iodide
  3. C) isopropyl chloride
  4. D) 3-chloropentane
  5. E) 3-iodo-3-methylpentane

Answer:  E

Section:  9-3

MCAT:  6.1

 

68) In the SN1 hydrolysis mechanism of (CH3)3CBr, there are ________ elementary steps, ________ distinct transition states, and ________ distinct intermediates.

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

Answer:  E

Section:  9-3

GLO:  G2

 

69) Provide the major organic product of the reaction below and a detailed, stepwise mechanism which accounts for its formation.

 

Answer:

 

Section:  9-3

MCAT:  6.2, 6.3

GLO:  G2

 

70) Provide the structure of the major organic products which result in the reaction below.

 

Answer:

 

Section:  9-3

MCAT:  6.2, 6.3

 

71) Provide the structure of the major organic product of the following reaction.

 

Answer:

 

Section:  9-3

MCAT:  6.2, 6.3

 

72) Provide the major organic product(s) in the reaction below.

 

Answer:

 

Section:  9-3

MCAT:  6.2, 6.3

 

73) Provide the major organic product(s) in the reaction below.

 

Answer:

 

Section:  9-3

 

74) Which of the following iodides undergoes SN1 solvolysis in water the fastest?

  1. A) 1-iodo-3-methylpentane
  2. B) 2-iodopentane
  3. C) 2-iodo-2-methylpentane
  4. D) 3-iodopentane
  5. E) 1-iodo-2,2-dimethylpentane

Answer:  C

Section:  9-3

MCAT:  6.1

 

75) Provide the major organic product(s) of the reaction shown.

 

Answer:

 

Section:  9-3

MCAT:  6.2, 6.3

 

76) Provide the major organic products(s) of the reaction shown.

 

Answer:

 

Section:  9-3

MCAT:  6.2, 6.3

 

77) Provide the major organic products(s) of the reaction shown.

 

Answer:

 

Section:  9-3

 

78) When (S)-2-bromobutane undergoes an SN2 reaction with CH3O-, the product is the compound shown below. What is/are the configuration(s) of the product(s) obtained from this reaction?

 

  1. A) S only
  2. B) R only
  3. C) a mixture of enantiomers with more R than S
  4. D) a mixture of enantiomers with more S than R
  5. E) equal mixture of R and S

Answer:  B

Section:  9-1

 

79) The specific rotation of optically pure (R)-sec-butyl alcohol is -13.52°. An optically pure sample of (R)-sec-butyl bromide was converted into the corresponding sec-butyl alcohol via an SN2 reaction. What is the specific rotation of the product, assuming 100% yield?

  1. A) -13.52°
  2. B) between 0° and -13.52°
  3. C) between 0° and +13.52°
  4. D) +13.52°
  5. E) zero

Answer:  D

Section:  9-1

MCAT:  5.4

GLO:  G2

 

80) SN1 reactions usually proceed with

  1. A) equal amounts of inversion and retention at the center undergoing substitution.
  2. B) slightly more inversion than retention at the center undergoing substitution.
  3. C) slightly more retention than inversion at the center undergoing substitution.
  4. D) complete inversion at the center undergoing substitution.
  5. E) complete retention at the center undergoing substitution.

Answer:  B

Section:  9-2

 

81) The specific rotation of optically pure (R)-C6H5CHOHCH3 is -42.3°. An optically pure sample of (R)-C6H5CHClCH3 was converted into the corresponding alcohol via an SN2 reaction. What is the specific rotation of the product?

  1. A) -42.3°
  2. B) between 0° and -42.3°
  3. C) between +42.3° and 0°
  4. D) +42.3°

Answer:  D

Section:  9-1

MCAT:  5.4

82) When (S)-1-bromo-1 phenylethane undergoes an SN1 reaction with methanethiol (CH3SH), the product is the compound shown. What is/are the configuration(s) of the product obtained from this reaction?

 

  1. A) S only
  2. B) R only
  3. C) a mixture of the enantiomers, with slightly more S than R
  4. D) a mixture of the enantiomers, with slightly more R than S

Answer:  D

Section:  9-2

MCAT:  6.1

 

83) Provide the structure of the major organic product of the following reaction.

 

Answer:

 

Section:  9-1

MCAT:  6.2, 6.3

 

84) Provide the structure of the major organic product(s) of the following reaction.

 

Answer:

 

Section:  9-3

MCAT:  6.2, 6.3

 

85) Identify the halide(s) that react in a SN2 reaction. You may choose more than one answer.

  1. A) benzyl bromide
  2. B) bromobenzene
  3. C) 1-bromo-1-butene
  4. D) 1-bromo-2-butene
  5. E) 2-bromo-2-phenylpropane

Answer:  A, D

Section:  9-1, 9-13

MCAT:  6.1

 

86) Identify the halide(s) that react in a SN1 reaction. You may choose more than one answer.

  1. A) benzyl bromide
  2. B) bromobenzene
  3. C) 1-bromo-1-butene
  4. D) 1-bromo-2-butene
  5. E) 2-bromo-2-phenylpropane

Answer:  A, D

Section:  9-3, 9-13

MCAT:  6.1

 

87) Which of the following can’t undergo nucleophilic substitution reactions?

 

  1. A) I
  2. B) II
  3. C) III
  4. D) IV
  5. E) V

Answer:  B

Section:  9-13

 

 

88) Which of the following is classified as a vinyl halide?

  1. A) CH3CH CHOH
  2. B) CH3CH CHCl
  3. C) CH3CH CHCH2Cl
  4. D) CH3CH2CH2CH2Br
  5. E) BrCH2CH CH2

Answer:  B

Section:  9-13

MCAT:  6.1

89) Explain why allyl chloride, shown below, undergoes SN1 reactions even though it is a 1° halide?

CH2 CHCH2Cl

allyl chloride

Answer:  Allyl chloride forms a relatively stable allylic carbocation with two contributing resonance structures.

Section:  9-13

MCAT:  6.3

GLO:  G7

 

90) Why are vinylic halides unreactive in both SN2 and SN1 reactions?

Answer:  Vinylic halides do not undergo SN2 reactions because as the nucleophile approaches the back side of the sp2 carbon it is repelled by the π electron cloud of the double bond. They do not undergo SN1 reactions because vinylic carbocations are prohibitively unstable (less stable than primary carbocations).

Section:  9-13

 

91) Identify the mechanism.

 

  1. A) SN1
  2. B) SN2
  3. C) E1
  4. D) E2
  5. E) none of the above

Answer:  A

Section:  9-12

MCAT:  6.1, 6.3

 

 

92) Identify the mechanism.

 

  1. A) SN1
  2. B) SN2
  3. C) E1
  4. D) E2
  5. E) none of the above

Answer:  B

Section:  9-12

MCAT:  6.3

93) Which of the following solvents is aprotic?

  1. A) CH3CH2OH
  2. B) CH3CH2CH2NH2
  3. C) CH3CH2OCH2CH3
  4. D) CH3CH2NHCH3

E)

 

Answer:  C

Section:  9-2

 

94) Which of the following solvents is protic?

A)

 

B)

 

  1. C) CH3CH2OCH3
  2. D) CH3CH2OH
  3. E) CH3CH2CH2Cl

Answer:  D

Section:  9-2

 

 

95) Protic and aprotic solvents are very similar as solvents except for their

  1. A) polarity.
  2. B) dielectric constant.
  3. C) ability to stabilize anions by hydrogen bonding.
  4. D) ability to stabilize cations by hydrogen bonding.
  5. E) ability to stabilize cations with unshared pairs of electrons.

Answer:  C

Section:  9-2

 

96) Which of the following best explains why SN1 reactions involving a neutral reactant are faster in polar solvents?

  1. A) The substrate is more soluble in polar solvents.
  2. B) The substrate is less soluble in polar solvents.
  3. C) The nucleophile is solvated by polar solvents.
  4. D) Solvation by polar solvents stabilizes the carbocation.
  5. E) Solvation by polar solvents stabilizes the transition state.

Answer:  E

Section:  9-14

97) Which of the following statements is generally true for SN1 reactions?

  1. A) Complete inversion of configuration occurs.
  2. B) These reactions are favored by nonpolar solvents.
  3. C) These reactions are favored by polar solvents.
  4. D) Reaction rates depend only on the concentration of the nucleophile.
  5. E) The mechanism is a one-step back attack.

Answer:  C

Section:  9-3

 

98) The hydrolysis of tert-butyl chloride proceeds more rapidly in a solvent mixture which is 70% water/30% acetone than in one which is 30% water/70% acetone. Why?

  1. A) The transition state in the carbocation formation step is better stabilized in the more polar solvent mixture.
  2. B) The reaction proceeds by an SN2 mechanism wherein the rate is increased by increasing the concentration of the nucleophile water.
  3. C) The reaction proceeds by an SN1 mechanism wherein the rate is increased by increasing the concentration of the nucleophile water.
  4. D) The solvent which contains a greater percentage of water is less polar, and this destabilizes the tert-butyl chloride.
  5. E) none of the above

Answer:  A

Section:  9-14

MCAT:  6.1

GLO:  G2

 

 

99) Consider the following reaction mechanism:

 

What effect will the following have on the rate?

  1. addition of Br-
  2. using a more polar solvent
  3. using a stronger nucleophile
  4. using a more concentrated nucleophile

Answer:  a. reaction will slow down because of competition with Nu-

  1. reaction will speed up because a more polar solvent assists in ionization and the formation of the carbocation
  2. no effect on SN1 reactions
  3. no effect on SN1 reactions

Section:  9-3

100) Explain why SN2 reactions proceed faster in the solvent dimethylsulfoxide than in ethanol?

CH3SOCH3          CH3CH2OH

dimethlysolfoxide           ethanol

Answer:  Dimethlysulfoxide is an aprotic solvent. Ethanol is a protic solvent which can hydrogen bond to the nucleophile, decreasing its nucleophilicity. Therefore, SN2 reactions favor aprotic solvents.

Section:  9-14

GLO:  G7

 

101) What type of solvent is best for SN2 reactions which employ anionic nucleophiles: polar, protic solvents; polar, aprotic solvents; or nonpolar solvents? Explain.

Answer:  Polar, aprotic solvents are best. These solvents have strong dipole moments to enhance solubility of the anionic species but lack the ability to solvate the anion by hydrogen bonding.

Section:  9-8

 

102) Draw the product for the following SN2 reaction.

 

Answer:

 

Section:  9-2, 9-14

GLO:  G7

 

 

103) When nucleophile and leaving group are contained in the same molecule, is intermolecular or intramolecular reaction favored? Explain.

Answer:  The answer depends on the concentration of the bifunctional molecule and the size of the ring that will be formed in the intramolecular reaction. The intramolecular reaction has the advantage of reacting groups being tethered close together and therefore not having to wander through the solvent to find each other. As a result, a low concentration of reactant favors intramolecular reaction over intermolecular. Additionally, if the intramolecular reaction would form a five- or six-membered ring, it would be highly favored since smaller ring formations are retarded by angle strain and larger ring formations are retarded by less favorable entropy considerations.

Section:  9-16

GLO:  G2, G7

 

104) Which of the following correctly describes SAM, a biological methylating agent?

  1. A) It contains a Cl bonded to a 1° carbon.
  2. B) It contains a methyl group bonded to a positively charged sulfur atom.
  3. C) It contains a methyl ether.
  4. D) it contains a methyl group bonded to an aromatic ring.
  5. E) It contains a Br bonded to a phosphorus atom.

Answer:  B

Section:  10-12

105) What is the leaving group in the reaction shown below?

 

  1. A) I
  2. B) II
  3. C) III
  4. D) IV
  5. E) V

Answer:  A

Section:  9-1

 

 

106) Give the product(s) for the reaction of (R)-2-bromopentane with methanol. You may choose more than one answer.

  1. A) (S)-2-methoxypentane
  2. B) (R)-2-methoxypentane
  3. C) (S)-2-ethoxypentane
  4. D) (R)-2-ethoxypentane
  5. E) (R)-2-pentanol
  6. F) (S)-2-pentanol

Answer:  A, B

Section:  9-3

MCAT:  6.1, 6.2

 

107) Give the SN2 product(s) for the reaction of (R)-2-bromopentane with an excess of sodium methoxide.

  1. A) (S)-2-methoxypentane
  2. B) (R)-2-methoxypentane
  3. C) (S)-2-ethoxypentane
  4. D) (R)-2-ethoxypentane
  5. E) (R)-2-pentanol
  6. F) (S)-2-pentanol

Answer:  A

Section:  9-1

MCAT:  6.1, 6.2

108) Give the name(s) of the product(s) of the SN2 reaction of 3-bromo-2,2-dimethylbutane with hydroxide.

  1. A) 2,2-dimethyl-1-butanol
  2. B) 3,3-dimethyl-2-butanol
  3. C) 3,3-dimethyl-1-butanol
  4. D) 2,3-dimethyl-2-butanol
  5. E) 2,3-dimethyl-1-butanol

Answer:  B

Section:  9-1

MCAT:  6.1, 6.2, 10.1

 

109) Give the name(s) of the product(s) of the SN1 reaction of 3-bromo-2,2-dimethylbutane with water.

  1. A) 2,2-dimethyl-1-butanol
  2. B) 3,3-dimethyl-2-butanol
  3. C) 3,3-dimethyl-1-butanol
  4. D) 2,3-dimethyl-2-butanol
  5. E) 2,3-dimethyl-1-butanol

Answer:  D

Section:  9-3

MCAT:  6.1, 6.2, 10.1

 

 

110) Give the name(s) of the product(s) for the following SN2 reaction.

 

  1. A) (S)-2-hexanol
  2. B) (R)-2-hexanol
  3. C) (S)-3-hexanol
  4. D) (R)-3-hexanol

Answer:  C

Section:  9-1

MCAT:  6.1, 6.2, 10.1

 

111) Give the name(s) of the product(s) for the following SN1 reactions. You may choose more than one answer.

 

  1. A) (S)-2-hexanol
  2. B) (R)-2-hexanol
  3. C) (S)-3-hexanol
  4. D) (R)-3-hexanol

Answer:  C, D

Section:  9-3

MCAT:  6.1, 6.2, 10.1

 

112) Which of the following carbocations does not rearrange?

A)

 

B)

 

C)

 

D)

 

  1. E) all the above

Answer:  E

Section:  6-7

MCAT:  4.2

 

113) Which of the following alkyl bromides undergoes solvolysis in methanol without rearrangement?

  1. A) (R)-2-bromo-3-ethylpentane
  2. B) (S)-2-bromo-3-ethylpentane
  3. C) (R)-3-bromo-2-methylpentane
  4. D) (S)-3-bromo-2-methylpentane
  5. E) 3-bromo-3-ethylpentane

Answer:  E

Section:  6-7, 9-3

MCAT:  6.1

 

114) Which of the following alkyl bromides is likely to undergo rearrangement by a 1, 2-methyl shift?

  1. A) benzyl bromide
  2. B) 2-bromo-3-ethylpentane
  3. C) 3-bromo-3-methylpentane
  4. D) 2-bromo-3, 3-dimethylpentane
  5. E) 3-bromo-2, 3-dimethylpentane

Answer:  D

Section:  6-7, 9-3

MCAT:  6.1

 

115) A 1,2-methyl shift occurs when which of the following iodides is heated in ethanol?

  1. A) C6H5CHICH(CH3)2
  2. B) (CH3)2CHCHICH3
  3. C) (CH3)3CCH2CH2I
  4. D) (CH3)2C CHI
  5. E) (CH3)3CCHICH2CH3

Answer:  E

Section:  6-7, 9-3

GLO:  G2

 

116) Provide the major organic product(s) in the reaction below.

 

Answer:

 

Section:  9-3

MCAT:  6.2

 

117) Provide the structure of the major organic product which results in the following reaction.

 

Answer:

 

Section:  9-3

GLO:  G2

 

118) List the following compounds in order of increasing reactivity in an SN1 reaction.

CH3Br, CH3CH2CH2I, (CH3)3CI, CH3CHBrCH3, CH3CHICH3

Answer:  CH3Br < CH3CH2CH2I < CH3CHBrCH3 < CH3CHICH3 < (CH3)3CI

Section:  9-3, 9-4

MCAT:  6.1

119) Which of the following are the elimination products of the reaction shown below?

CH3CH2Br + -OH → ?

  1. A) CH3CH2Br+H + O-
  2. B) HOCH2CH2Br
  3. C) CH3CH2OH + Br-
  4. D) CH2 CH2 + Br- + H2O
  5. E) CH2 CHBr + H2O

Answer:  D

Section:  9-7

 

120) Draw the alkene product which results when 1-bromopentane is heated in acetone containing NaOH. Give a detailed, step-by-step mechanism for the production of this compound.

Answer:

 

Section:  9-7

MCAT:  7.4

 

121) Give the mechanism of the reaction shown below.

 

Answer:

 

Section:  9-7

MCAT:  7.4

GLO:  G2

 

122) Give the mechanism of the reaction shown below.

 

Answer:

 

Section:  9-7

MCAT:  7.4

 

123) What is the most reactive alkyl halide for elimination reactions?

  1. A) 1-chlorobutane
  2. B) 1-fluorobutane
  3. C) 1-iodobutane
  4. D) 1-bromobutane

Answer:  C

Section:  9-7

MCAT:  6.1

 

124) Which alkyl halide reacts the fastest in an E2 reaction?

  1. A) 2-chloro-2-methylbutane
  2. B) 1-chlorobutane
  3. C) 1-chloro-2-methylbutane
  4. D) 2-chlorobutane
  5. E) chloromethane

Answer:  A

Section:  9-7

MCAT:  6.1

 

125) Give the major product for the following E2 reaction.

 

A)

 

B)

 

C)

 

D)

 

  1. E) none of the above

Answer:  A

Section:  9-7

MCAT:  7.4

 

 

126) Give the major product for the E2 reaction.

 

A)

 

B)

 

C)

 

D)

 

E)

 

Answer:  D

Section:  9-7

MCAT:  7.4

 

127) Give the major product for the following E2 reaction.

 

A)

 

B)

 

C)

 

D)

 

E)

 

Answer:  A

Section:  9-7

MCAT:  7.4

 

128) Which of the following compounds undergoes E2 reactions with the fastest rate?

A)

 

  1. B) CH3CH2CH2Cl
  2. C) CH3CH2CH2I

D)

 

  1. E) CH3CH2CH2Br

Answer:  D

Section:  9-7

MCAT:  6.1, 7.4

 

129) Which of the following bases gives the highest anti-Zaitsev product in E2 reactions when reacted with 2-bromo-2, 3-dimethylbutane?

A)

 

B)

 

C)

 

D)

 

E)

 

Answer:  E

Section:  9-7

MCAT:  6.1

GLO:  G2

130) What is the major product of the following E2 reaction?

 

A)

 

  1. B) CH3CH2CH CH2

C)

 

D)

 

E)

 

Answer:  C

Section:  9-7

MCAT:  7.4

 

131) How many distinct alkene products are possible when the alkyl iodide below undergoes E2 elimination?

 

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

Answer:  E

Section:  9-7

MCAT:  7.4

GLO:  G2

 

132) Which of the alkyl chlorides listed below undergoes dehydrohalogenation in the presence of a strong base to give 2-pentene as the only alkene product?

  1. A) 1-chloropentane
  2. B) 2-chloropentane
  3. C) 3-chloropentane
  4. D) 1-chloro-2-methylbutane
  5. E) 1-chloro-3-methylbutane

Answer:  C

Section:  9-7

MCAT:  6.1, 7.4

GLO:  G2

 

133) When 2-bromo-3-methyl-1-phenylbutane is treated with sodium methoxide, why is the major product 3-methyl-1-phenyl-1-butene?

  1. A) SN2 predominates over E2.
  2. B) E1 predominates over E2.
  3. C) The bulkiness of the methoxide results in the less substituted alkene.
  4. D) The newly formed double bond in this compound is conjugated with the phenyl ring.
  5. E) The less substituted alkene is always more stable than the more substituted alkene.

Answer:  D

Section:  9-12

MCAT:  6.1, 7.4

GLO:  G2

 

134) What is the major organic product of the following reaction?

 

  1. A) 2,3-dimethyl-1-hexene
  2. B) 2,3-dimethyl-2-hexene
  3. C) 2-isopropyl-1-pentene
  4. D) (Z)-2,3-dimethyl-3-hexene
  5. E) (E)-2,3-dimethyl-3-hexene

Answer:  B

Section:  9-7

MCAT:  7.1

 

135) What is the major organic product of the following reaction?

 

  1. A) 2,3-dimethyl-1-hexene
  2. B) 2,3-dimethyl-2-hexene
  3. C) 2-isopropyl-1-pentene
  4. D) (Z)-2,3-dimethyl-3-hexene
  5. E) (E)-2,3-dimethyl-3-hexene

Answer:  C

Section:  9-7

MCAT:  7.1

 

136) Which of the following halides is most reactive in an E2 reaction with sodium methoxide?

  1. A) (CH3)3CCH2I
  2. B) (CH3)2CHCHICH3
  3. C) (CH3)2CHCH2Br
  4. D) (CH3)2CHCH2Cl
  5. E) (CH3)2CHCH2CH2Cl

Answer:  B

Section:  9-7

 

137) Which of the following halides is least reactive in an E2 reaction with sodium methoxide?

  1. A) (CH3)3CCH2I
  2. B) (CH3)2CHCHICH3
  3. C) (CH3)2CHCH2Br
  4. D) (CH3)2CHCH2Cl
  5. E) (CH3)2CHCH2CH2Cl

Answer:  A

Section:  9-7

MCAT:  7.4

 

138) Which of the following statements is true concerning the E2 reactions of alkyl fluorides?

  1. A) Alkyl fluorides react more readily in E2 reactions than do alkyl iodides.
  2. B) The transition state of this E2 reaction resembles a carbanion rather than an alkene.
  3. C) The C-F bond is the weakest carbon-halogen bond so SN2 will always predominate over E2 in the reactions of alkyl fluorides.
  4. D) Alkyl fluorides react to form the most stable carbocation intermediate.
  5. E) Alkyl fluorides cannot adopt the proper stereochemical alignment for an E2 reaction to occur.

Answer:  B

Section:  9-7

GLO:  G2

 

139) When 1-iodo-1-methylcyclohexane is treated with NaOCH2CH3, the more highly substituted alkene product predominates. When KOC(CH3)3 is used instead, the less highly substituted alkene product predominates. Offer an explanation.

Answer:  The unhindered ethoxide produces the more stable alkene product (ie, the more highly substituted alkene possible). When the bulky t-butoxide is used, the most accessible hydrogen is removed. This results in the least highly substituted alkene possible.

Section:  9-7

GLO:  G7

 

140) Provide the structure of the major organic product which results when 2-bromo-2-methylbutane is treated with sodium ethoxide.

Answer:

 

Section:  9-7

MCAT:  6.1

 

141) Draw all likely alkene products in the following reaction and circle the product you expect to predominate.

 

Answer:

 

Section:  9-7

MCAT:  7.2, 7.4

 

142) Draw all likely alkene products in the following reaction and circle the product you expect to predominate.

 

Answer:

 

Section:  9-7

MCAT:  7.2, 7.4

 

143) Draw all likely alkene products in the following reaction and circle the product you expect to predominate.

 

Answer:

 

Section:  9-7

MCAT:  7.2, 7.4

 

144) Supply the missing alkyl halide reactant in the elimination reactions shown below.

 

Answer:

  1. a) bromomethylcyclohexane
  2. b) CH3CH2CHBrCH2CH3
  3. c) CH3CH2CH(CH3)CH2Br

Section:  9-7

GLO:  G2

 

145) Provide the structure of the major organic product of the following reaction.

 

Answer:

 

Section:  9-7

 

146) Provide the structure of the major organic product of the following reaction.

 

Answer:

 

Section:  9-7

GLO:  G2

 

147) Provide the major organic product of the following reaction.

 

Answer:

 

Section:  9-7

 

148) Provide the major organic product of the following reaction.

 

Answer:

 

Section:  9-7

GLO:  G2

 

149) Provide the major organic product of the following reaction.

 

Answer:

 

Section:  9-7

GLO:  G2

 

150) Provide the major organic product of the following reaction.

 

Answer:

 

Section:  9-7

 

151) Provide the major organic product of the following reaction.

 

Answer:

 

Section:  9-7

GLO:  G2

 

152) Which of the following alkyl halides undergoes E1 reactions with the fastest rate?

A)

 

B)

 

C)

 

D)

 

  1. E) CH3I

Answer:  D

Section:  9-8

 

 

153) Which of the following alkyl halides forms the most stable carbocation when it undergoes an E1 reaction?

 

  1. A) I
  2. B) II
  3. C) III
  4. D) IV
  5. E) V

Answer:  D

Section:  9-13

MCAT:  4.2, 15.2

154) Which of the following statements correctly describe(s) E1 reactions of alkyl halides (RX)?

  1. Rate = k[base]
  2. Rate = k[base][RX]

III.           Rate = k[RX]

  1. The reactions occur in two distinct steps.
  2. Rearrangements are sometimes seen.
  3. A) II and IV
  4. B) III and V
  5. C) I, IV, and V
  6. D) I only
  7. E) III, IV, and V

Answer:  E

Section:  9-8

MCAT:  6.3

 

 

155) Consider the following experimental data for the rate of the reaction given below:

 

 

Experiment #1  [Alkyl Halide]     [Base]   Rate

1              0.01        0.01        1

2              0.02        0.01        2

3              0.01        0.02        1

 

What is the mechanism for the reaction?

  1. A) first order, SN1
  2. B) first order, SN2
  3. C) first order, E1
  4. D) first order, E2
  5. E) none of the above

Answer:  C

Section:  9-12

MCAT:  6.3

GLO:  G3

 

156) Which of the following correctly reflects relative stabilities of carbocations?

  1. A) 3° allylic > 2° > 1° benzylic
  2. B) methyl > 2° benzylic > 3°
  3. C) 3° benzylic > vinyl > 1°
  4. D) 2° allylic > 2° > vinyl
  5. E) 1° benzylic > 3° > 3° allylic

Answer:  D

Section:  9-13

MCAT:  4.2, 15.2

 

157) When 1-bromo-2,2-dimethylcyclopentane is heated in ethanol, one of the products which results is shown below. Provide a detailed, stepwise mechanism for the production of this compound, and give the name of the mechanism by which it is produced.

 

Answer:

 

Section:  9-8

MCAT:  6.1

 

158) List the following compounds in order of increasing reactivity in an E1 elimination.

CH3CH2CHBrCH3, CH3CH2CH2CH2Br, (CH3)3CBr

Answer:  CH3(CH2)3Br < CH3CH2CHBrCH3 < (CH3)3CBr

Section:  9-8

MCAT:  6.1

 

 

159) Give the mechanism of the reaction shown below.

 

Answer:

 

Section:  9-8

GLO:  G2

 

 

160) Give the mechanism of the reaction shown below.

 

Answer:

 

Section:  9-8

GLO:  G2

 

161) Identify the alkyl halide that reacts the fastest in a E1 reaction.

A)

 

  1. B) CH2 CHCl

C)

 

D)

 

  1. E) CH3CH2CH2Cl

Answer:  D

Section:  9-8

MCAT:  6.1, 15.2

 

 

162) Give the major product for the following E1 reaction.

 

A)

 

B)

 

C)

 

D)

 

E)

 

Answer:  D

Section:  9-8

 

 

163) Dehydrohalogenation of 2-bromobutane in the presence of a strong base proceeds via which of the following mechanistic pathways?

  1. A) SN1
  2. B) SN2
  3. C) E1
  4. D) E2
  5. E) none of the above

Answer:  D

Section:  9-12

MCAT:  6.1

 

164) Provide the structure of the major organic product in the following reaction.

 

Answer:

 

Section:  9-10

MCAT:  7.4

165) Why is the E1 not a likely mechanism when 1-chloropentane is heated in ethanol?

Answer:  Primary halides cannot undergo E1 reactions because of the difficulty encountered in forming primary carbocations.

Section:  9-12

MCAT:  4.2

GLO:  G7

 

166) Which of the following is least likely to be found in the product mixture which results when 2-iodopentane reacts with sodium ethoxide in ethanol?

  1. A) 1-ethoxypentane
  2. B) 2-ethoxypentane
  3. C) (Z)-2-pentene
  4. D) (E)-2-pentene
  5. E) 1-pentene

Answer:  A

Section:  9-12

MCAT:  6.1, 7.1

 

 

167) What is the major product which results when (2R,3S)-2-chloro-3-phenylbutane is treated with sodium methoxide in methanol?

  1. A) (E)-2-phenyl-2-butene
  2. B) (Z)-2-phenyl-2-butene
  3. C) (S)-3-phenyl-1-butene
  4. D) (R)-3-phenyl-1-butene
  5. E) (R)-2-methoxy-2-phenylbutane

Answer:  B

Section:  9-12

MCAT:  6.1, 7.1

 

168) Why is the alkyl halide below not capable of undergoing an E2 reaction upon treatment with sodium ethoxide?

 

  1. A) Br- is too poor a leaving group.
  2. B) The substrate is too hindered.
  3. C) Too much angle strain would be present in the alkene product.
  4. D) Sodium ethoxide is a poor base to use in E2 reactions.
  5. E) The C-H and C-Br bonds which need to break cannot achieve an anti-periplanar orientation.

Answer:  E

Section:  9-11

MCAT:  7.4

 

169) Which of the compounds shown below is/are the product(s) of this reaction?

 

  1. A) I only
  2. B) II only
  3. C) I and II are of equal yield.
  4. D) I is major, II is minor.
  5. E) I is minor, II is major.

Answer:  A

Section:  9-11

MCAT:  7.4

 

170) Which of the following compounds is/are the products of the following reaction?

 

  1. A) I only
  2. B) II only
  3. C) I and II are of equal yield.
  4. D) I is major, II is minor.
  5. E) I is minor, II is major.

Answer:  E

Section:  9-11

MCAT:  7.4

 

171) Provide the structure of the major organic product which results in the following reaction.

 

Answer:

 

Section:  9-11

MCAT:  7.4

 

172) Provide the structure of the major organic product which results in the following reaction.

 

Answer:

 

Section:  9-11

MCAT:  7.4

 

173) Which diastereomer of 1-bromo-4-t-butylcyclohexane, the cis or the trans, undergoes elimination more rapidly when treated with sodium ethoxide? Explain your answer.

Answer:  The cis isomer reacts more quickly. An axial orientation of the C-Br bond is required for E2 in six-membered ring systems. In order for this to occur in the trans isomer, the bulky t-butyl group must also assume an axial orientation; this requires substantial energy of activation.

Section:  10-7

MCAT:  3.5, 7.4

 

174) Provide the structure of the major organic product which results in the following reaction.

 

Answer:

 

Section:  9-11

MCAT:  7.4

 

175) Provide the structure of the major elimination product which results when the alkyl bromide below is heated in ethanol.

 

Answer:

 

Section:  9-11

GLO:  G2

 

 

176) Give the major product for the following E1 reaction.

 

A)

 

B)

 

C)

 

D)

 

  1. E) no reaction

Answer:  A

Section:  9-8

 

 

177) Give the major product for the following E2 reaction.

 

A)

 

B)

 

C)

 

D)

 

  1. E) no reaction

Answer:  E

Section:  9-7

MCAT:  7.4

 

 

178) What is the major product of the following reaction?

 

  1. A) CH2 CHCH2CH3
  2. B) CH3CH CHCH3

C)

 

  1. D) CH3CH2CH2CH2OCH2CH3

E)

 

Answer:  B

Section:  9-12

MCAT:  6.3

179) What is the major product of the following reaction?

 

  1. A) CH2 CHCH2CH3
  2. B) CH3CH CHCH3

C)

 

  1. D) CH3CH2CH2CH2OCH2CH3

E)

 

Answer:  C

Section:  9-12

MCAT:  6.3

 

180) What is the major product of the following reaction?

 

  1. A) I
  2. B) II
  3. C) III
  4. D) IV
  5. E) V

Answer:  E

Section:  9-12

 

181) What is/are the product(s) of the following reaction?

 

A)

 

  1. B) CH2 CH2

C)

 

  1. D) A and B
  2. E) A and C

Answer:  C

Section:  9-12

 

182) Predict the two most likely mechanisms for the reaction of 2-iodohexane with sodium ethoxide.

  1. A) SN2 and SN1
  2. B) E1 and E2
  3. C) SN2 and E2
  4. D) E1 and SN1
  5. E) E2 and SN1

Answer:  C

Section:  9-12

MCAT:  6.1

 

 

183) Predict the two most likely mechanisms which occur when 2-iodohexane is heated in ethanol.

  1. A) SN2 and SN1
  2. B) E1 and E2
  3. C) SN2 and E2
  4. D) E1 and SN1
  5. E) E2 and SN1

Answer:  D

Section:  9-12

MCAT:  6.1

184) What is/are the product(s) of the following reaction?

 

A)

 

  1. B) CH2 CH2

C)

 

  1. D) A and B
  2. E) A and C

Answer:  D

Section:  9-12

GLO:  G2

 

 

185) What mechanism predominates in the reaction below?

 

  1. A) SN2
  2. B) SN1 without rearrangement
  3. C) SN1 with rearrangement
  4. D) E2
  5. E) E1

Answer:  A

Section:  9-12

MCAT:  6.2, 6.3

186) What mechanism predominates in the reaction below?

 

  1. A) SN2
  2. B) SN1 without rearrangement
  3. C) SN1 with rearrangement
  4. D) E2
  5. E) E1

Answer:  C

Section:  9-12

MCAT:  6.2, 6.3

 

 

187) What mechanism predominates in the reaction below?

 

  1. A) SN2
  2. B) SN1 without rearrangement
  3. C) SN1 with rearrangement
  4. D) E2
  5. E) E1

Answer:  D

Section:  9-12

MCAT:  6.2, 6.3

188) Which of the following is least likely to be found in the product mixture which results when the alkyl iodide below is heated in water?

 

  1. A) I
  2. B) II
  3. C) III
  4. D) IV
  5. E) V

Answer:  D

Section:  9-12

GLO:  G2

 

 

189) Which base, ammonia (NH3) or triethylamine [(CH3CH2)3N], would be a better choice for use in converting 1-chlorohexane to 1-hexene? Explain briefly.

Answer:  Triethylamine. Amines can serve as both nucleophiles and as bases in reactions with alkyl halides. Increasing the steric bulk about the nitrogen diminishes the nucleophilicity while allowing the amine to continue to function effectively as a base.

Section:  9-12

MCAT:  6.1, 7.1

GLO:  G7

190) Provide the structure of the major organic product of the following reaction.

 

Answer:

 

Section:  9-12

GLO:  G2

 

191) Can primary alkyl halides react by SN2, SN1, E2, and E1 mechanisms? Are any of these mechanisms prohibited? What conditions favor a particular mechanism?

Answer:  Only SN2 and E2 pathways are available to primary halides. SN1 and E1 cannot occur due to the instability of primary carbocations. SN2 will typically predominate over E2 unless there is steric hindrance in the alkyl halide or nucleophile/base.

Section:  9-12

GLO:  G2, G7

 

192) What reaction mechanism predominates when 1-bromo-1-propylcyclopentane is treated with sodium methoxide in methanol?

Answer:  E2

Section:  9-12

MCAT:  6.1

 

193) What reaction mechanism predominates when 1-bromo-1-propylcyclopentane is heated in ethanol?

Answer:  SN1

Section:  9-12

MCAT:  6.1

 

194) Provide the major organic product(s) in the reaction below.

 

Answer:

 

Section:  9-12

 

195) Give the major product(s) for the following reaction. You may choose more than one answer.

 

A)

 

B)

 

C)

 

D)

 

E)

 

 

F)

 

Answer:  A, E

Section:  9-12

 

 

196) Give the major organic product(s) for the following reaction. You may choose more than one answer.

 

A)

 

B)

 

C)

 

D)

 

E)

 

 

F)

 

Answer:  C, F

Section:  9-12

 

197) Give the best answer for the reaction.

 

  1. A) CH3CH2OCH3
  2. B) CH3CH2OCH2CH3
  3. C) CH3CH2OCH2CH2CH3
  4. D) CH3CH2CH2OCH2CH2CH3
  5. E) CH3CH2CH2OCH2CH2CH2CH3

Answer:  C

Section:  9-15

 

 

198) Give the major product for the following reaction.

 

A)

 

B)

 

C)

 

D)

 

E)

 

Answer:  C

Section:  9-12

MCAT:  7.4

GLO:  G2

 

 

199) Provide the major organic product of the following reaction.

 

Answer:

 

Section:  9-12

 

200) Provide the major organic product of the following reaction.

 

Answer:

 

Section:  9-12

MCAT:  6.2

201) Starting with 2-butene, which of the following is the best method for preparing 2-butyne?

  1. A) HBr; H2/Ni; Zn/H+
  2. B) HBr; Zn/H+; H2/Ni
  3. C) Br2/CCl4; Zn/H+; H2/Ni
  4. D) Br2/CCl4; 2NaNH2
  5. E) HBr; NaNH2

Answer:  D

Section:  9-17

MCAT:  7.1, 9.1

GLO:  G2

 

 

202) Which of the following alkyl chlorides would undergo substitution most rapidly when treated with NaCCH: chloroethane, 2-chloropropane, or 1-chloro-2,2-dimethylpropane? Provide the structure of the substitution product.

Answer:  Chloroethane reacts most rapidly; CH3CH2C CH is produced.

Section:  9-12

MCAT:  6.1

 

203) Show the best way to prepare CH3OCH(CH3)2 by an SN2 reaction.

Answer:  CH3I + NaOCH(CH3)2

Section:  9-15

GLO:  G2

 

204) Name the products of the following SN2 reactions.

 

Answer:

  1. a) 3-cyclopentyl-1-propyne
  2. b) 2-iodo-4-methylpentane
  3. c) 1-methoxypropane

Section:  9-1

MCAT:  6.1, 9.1, 14.1

 

205) Identify the major organic product for the reaction.

 

A)

 

  1. B) CH3CH2—C CCH3
  2. C) CH3CH C CHCH3
  3. D) CH3CH2—CH2—CH CH2
  4. E) CH3CH2—CH2—CH CH

Answer:  B

Section:  9-7

 

206) Identify the major organic product for the reaction.

 

A)

 

  1. B) CH3CH2—C CCH3
  2. C) CH3CH C CHCH3
  3. D) CH3CH2—CH2—CH CH2
  4. E) CH3CH2—CH2—CH CH

Answer:  B

Section:  9-7

GLO:  G2

 

207) What is the major product of the following reaction?

 

  1. A) CH2 CHCH2CH CH2

B)

 

  1. C) CH2 CHCH CHCH3

D)

 

  1. E) CH2 CHCH2CH2CH2OH

Answer:  C

Section:  9-12

GLO:  G2

 

208) Which sequence of reagents works best to convert 3-hexene to 3-hexyne?

  1. A) 1. HCl 2. NaNH2
  2. B) 1. BH3∙THF 2. HO-, H2O2 3. NaNH2
  3. C) 1. NaNH2 2. HI 3. H3O+
  4. D) 1. Br2, CH2Cl2 2. NaNH2 (excess)
  5. E) 1. Cl2, CH2Cl2 2. NaCN (excess)

Answer:  D

Section:  9-17

GLO:  G2

 

209) Which sequence of reagents works best to convert 1-bromobutane to hexane?

  1. A) 1. NaOCH3, CH3OH 2. NaCN 3. Na, NH3
  2. B) 1. NaC CH 2. H2 (excess), Pd/C
  3. C) 1. CH3CH2OH, delta 2. H2 (excess), Pd/C
  4. D) 1. NaCN 2. BH3*THF 3. HO-, H2O2
  5. E) 1. NaC CCH2CH3 2. Na, NH3

Answer:  B

Section:  9-17

 

210) Provide the major organic product(s) in the reaction below.

 

Answer:

 

Section:  9-7

 

211) Provide the major organic product(s) in the reaction below.

 

Answer:

Section:  9-7

 

212) Give the product from the reaction of 1-pentene with the following reagents.

  1. Cl2
  2. -OH
  3. NaNH2
  4. CH3CH2Br

Answer:  3-heptyne

Section:  9-17

MCAT:  7.1, 8.2

 

213) Geraniol is a fragrant alcohol found in roses. It is biologically synthesized from geranyl phosphate by SN1. What is the leaving group in this reaction?

 

Answer:

 

Section:  9-3

GLO:  G2

 

214) Show the carbocation intermediate formed during the synthesis of geraniol by SN1 reaction.

 

Answer:

Section:  9-3

 

215) Draw product of the following intramolecular SN2 reaction.

 

Answer:

Section:  9-1, 9-15

MCAT:  6.2

 

216) Predict the nucleophile in this reaction.

 

Answer:

Section:  9-1

 

217) In a SN1 reaction, carbocation is a(n)

  1. A) transition state.
  2. B) catalyst.
  3. C) solvent.
  4. D) intermediate.
  5. E) side product.

Answer:  D

Section:  9-3

 

218) The rate of an SN1 reaction is fastest in

  1. A) 100% ethanol.
  2. B) 80% ethanol and 20% water.
  3. C) 50% ethanol and 50% water.
  4. D) 25% ethanol and 75% water.
  5. E) 100% water.

Answer:  E

Section:  9-14

GLO:  G2

 

219) The following reaction involves an

 

  1. A) intramolecular SN2 reaction.
  2. B) intermolecular SN2 reaction.
  3. C) intramolecular SN1 reaction.
  4. D) intermolecular SN1 reaction.
  5. E) any of the above.

Answer:  A

Section:  9-15

 

220) How would you obtain the following two products from 1-bromo-1-methylcyclohexane?

 

Answer:

  1. (CH3)3COK
  2. O3
  3. Me2S

Section:  9-7, 9-17

GLO:  G2

 

 

221) How many different types of  hydrogens are present in the following molecule?

 

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

Answer:  A

Section:  9-7

222) How many different types of  hydrogens are present in the following molecule?

 

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

Answer:  C

Section:  9-7

 

223) How many distinct alkene products are formed in this reaction?

 

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

Answer:  B

Section:  9-7

GLO:  G2

 

 

224) Which of the following is not true for a SN1 mechanism?

  1. A) The rate is dependent on the nucleophile.
  2. B) The rate is fastest in highly polar solvents.
  3. C) proceeds with a carbocation intermediate
  4. D) is a two step reaction
  5. E) Methyl iodide will not undergo this reaction.

Answer:  A

Section:  9-3

 

225) Draw the product of the following reaction.

 

Answer:

 

Section:  9-7

226) How would you obtain the following products from 1-bromo-1-methylcyclohexane?

 

Answer:

  1. (CH3)3COK
  2. BH3/THF
  3. NaOH, H2O2

Section:  9-7, 9-17

MCAT:  6.1, 8.2

 

227) How would you convert 1-bromo-1,4,4-trimethylcyclohexane to the following compound?

 

Answer:

  1. CH3ONa
  2. O3
  3. Me2S

Section:  9-7, 9-17

MCAT:  6.2

 

 

228) Predict the mechanism of the reaction and the reagent needed to carry out the following transformation.

 

Answer:  SN1

CH3OH

Section:  9-12

 

229) What would be the product of this reaction? Also, provide the name of the mechanism (SN2, SN1, E2 or E1).

 

Answer:  No reaction. It should undergo E2 (tertiary alkyl halide and strong base), but there are no beta hydrogens available.

Section:  9-12

GLO:  G2

230) Draw the product of the following reaction.

 

Answer:

 

Section:  9-10

MCAT:  7.4

 

 

231) Draw the product of the following reaction.

 

Answer:

 

Section:  9-10

MCAT:  7.4

 

232) How would you obtain the following product from 1-bromo-1-methylcyclohexane?

 

Answer:

  1. (CH3)3COK
  2. H2/Pd

Section:  9-7, 9-17

MCAT:  6.1, 8.1