Quiz 10 Flashcards
If the conjugated diene is not symmetrical, what do you do?
Protonate to form the more stable carbocation
The thermodynamic product predominates when the reaction is…
reversible
The kinetic product predominates when the reaction is….
irreversible
1,2-addition
most of the time, the 1,2 addition product is the …
kinetic product
most of the time, the 1,4-addition product is the
thermodynamic product
6) Which of the following pairs are resonance structures?
C) III
7) Which of the following pairs are resonance structures?
C) III
8) Which of the following is not a resonance structure of the species shown?
D) IV
9) In which of the following does resonance delocalization of electron density not play a role?
A) allyl cation
B) benzyl anion
C) CO32-
D) O3
E) cyclohexyl radical
E) cyclohexyl radical
11) Due to electron delocalization, one would predict that the carbon-oxygen bond in acetamide, CH3CONH2, ________.
A) is nonpolar
B) has more double bond character than the carbon-oxygen bond of acetone, (CH3)2CO
C) is longer than the carbon-oxygen bond of dimethyl ether, (CH3)2O
D) is longer than the carbon-oxygen bond of acetone, (CH3)2CO
E) is formed by overlapping sp3 orbitals
D) is longer than the carbon-oxygen bond of acetone, (CH3)2CO
33) Identify the most stable structure(s).
Answer: A
36) Which of the following statements concerning resonance contributors and resonance hybrids is not correct?
A) The fewer nearly equivalent resonance contributors are in the structure, the greater the resonance energy.
B) A resonance hybrid is more stable than the predicted stability of any of its resonance contributors.
C) The greater the number of relatively stable resonance contributors, the greater the resonance energy.
D) The greater the predicted stability of a resonance contributor, the more it contributes to the resonance hybrid.
E) none of the above
A) The fewer nearly equivalent resonance contributors are in the structure, the greater the resonance energy.
38) Aromatic molecules contain ________ π electrons.
A) no
B) 4n + 2 (with n an integer)
C) 4n + 2 (where n = 0.5)
D) 4n (with n an integer)
E) unpaired
B) 4n + 2 (with n an integer)
43) Which of the following is an aromatic hydrocarbon?
C) III
44) Which of the following is aromatic?
C) III
45) Which of the structures below would be aromatic?
C) III and IV
46) Which of the following is aromatic?
B) II
47) Which of the following is aromatic?
A) cyclopentadienyl cation
B) 1,3-cyclohexadiene
C) cyclobutenyl anion
D) 1,3,5-hexatriene
E) cycloheptatrienyl cation
E) cycloheptatrienyl cation
49) Which of the following compounds is aromatic?
D) IV
50) Which of the following is aromatic?
A) I
55) Which of the following is antiaromatic?
D) IV
64) Which of the following statements about the π molecular orbital description of cyclobutadiene is not correct?
A) Cyclobutadiene has two degenerate nonbonding π molecular orbitals.
B) Cyclobutadiene has a single bonding π molecular orbital.
C) Cyclobutadiene has two electrons in nonbonding π molecular orbitals.
D) Cyclobutadiene has one electron in an antibonding π molecular orbital which makes it antiaromatic.
E) none of the above
D) Cyclobutadiene has one electron in an antibonding π molecular orbital which makes it antiaromatic.
66) Which of the following is an allylic cation?
B) II
67) Which of the following is a benzylic cation?
D) IV
68) Which of the following is the most stable cation?
C) III
69) How many allylic hydrogen atoms are present in the following molecule?
E) zero
70) How many benzylic hydrogens are present in the following molecule?
E) zero
71) Which of the following is the most stable diene?
C) III
74) What descriptive term is applied to the type of diene represented by 2,4-hexadiene?
A) conjugated diene
B) cumulated diene
C) isolated diene
D) alkynyl diene
E) none of the above
A) conjugated diene
75) What descriptive term is applied to the type of diene represented by 1, 5-octadiene?
A) conjugated diene
B) cumulated diene
C) isolated diene
D) alkynyl diene
E) none of the above
C) isolated diene
76) Which of the following is a cumulated diene?
C) III
77) Which of the following is a conjugated diene?
A) I
86) Identify the most stable carbocation.
87) Identify the most stable carbocation.
96) Which of the following is/are the major product(s) of the following reaction?
A) I
97) Which of the following is the strongest acid?
98) Which of the following is the strongest acid?
D) IV
103) Which of the following is/are the main product(s) of the following reaction?
E) A and C