Deck 21: Benzene and the Concept of Aromaticity

Question 1

What is the correct assignment of the names of the following fused arenes?

A)1 = naphthalene; 2 = anthracene; 3 = pyrene
B)1 = naphthalene; 2 = phenanthrene; 3 = coronene
C)1 = naphthalene; 2 = anthracene; 3 = benzo[a]pyrene
D)1 = anthracene; 2 = naphthalene; 3 = coronene

Answer 1

1 = naphthalene; 2 = anthracene; 3 = pyrene

Question 2

Which is the correct assignment of the names of the following substituted benzenes?

A)1 = phenol; 2 = m-cresol; 3 = toluene
B)1 = m-cresol; 2 = resorcinol; 3 = m-xylene
C)1 = anisole; 2 = catechol; 3 = m-xylene
D)1 = m-cresol; 2 = anisole; 3 = cumene

Answer 2

1 = m-cresol; 2 = resorcinol; 3 = m-xylene

Question 3

What is the correct assignment of the names of the following substituted benzenes?

A)1 = phenol; 2 = aniline; 3 = anisole
B)1 = benzaldehyde; 2 = anisole; 3 = toluene
C)1 = anisole; 2 = xylene; 3 = toluene
D)1 = anisole; 2 = aniline; 3 = toluene

Answer 3

1 = anisole; 2 = aniline; 3 = toluene

Question 4

Which of the following represents the energy levels of the molecular orbitals of benzene?

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

Question 5

Which of the following statements is not true about the structure of benzene?

A)six atomic 2p-orbitals overlap to form six $\pi$ -molecular orbitals
B)there are three bonding $\pi$ -molecular orbitals and three $\pi$ -antibonding molecular orbitals
C)the ground state electronic configuration of benzene has six electrons in three $\pi$ -bonding molecular orbitals
D)the bonds alternate in length around the ring

Question 6

What is the hybridization of the nitrogen atom of pyridine?

A)s
B)sp
C)sp²
D)sp³

Question 7

What is the correct assignment of the names of the following heterocycles?

A)1 = pyrrole; 2 = thiophene; 3 = pyridine
B)1 = thiophene; 2 = furan; 3 = pyrrole
C)1 = pyridine; 2 = thiophene; 3 = furan
D)1 = pyridine; 2 = thiophene; 3 = pyrrole

Question 8

What is the hybridization of the oxygen atom of furan?

A)s
B)sp
C)sp²
D)sp³

Question 9

Which of the following compounds is aromatic?

A)ethane
B)cyclobutadiene
C)benzene
D)cyclooctatetraene

Question 10

What is the IUPAC name of the following compound?

A)1-bromo-2-fluoro-4-toluene
B)4-bromo-2-fluorotoluene
C)2-bromo-4-fluorophenol
D)4-bromo-2-fluoroxylene

Question 11

What is the IUPAC name of the following compound?

A)2,4-dibromotoluene
B)2,4-dibromophenol
C)2,4-dibromohydroxybenzene
D)4,6-dibromophenol

Question 12

What is the correct assignment of the names of the following heterocycles?

A)1 = pyrrole; 2 = thiophene; 3 = pyridine
B)1 = thiophene; 2 = furan; 3 = pyrrole
C)1 = furan; 2 = pyrrole; 3 = thiophene
D)1 = furan; 2 = thiophene; 3 = pyrrole

Question 13

What is the correct assignment of the names of the following substituted benzenes?

A)1 = styrene; 2 = benzaldehyde; 3 = cumene
B)1 = anisole; 2 = benzaldehyde; 3 = toluene
C)1 = styrene; 2 = xylene; 3 = toluene
D)1 = aniline; 2 = phenol; 3 = cumene

Question 14

Which orbital contains the lone pair on the nitrogen atom of pyrrole?

A)s
B)p
C)sp
D)sp²

Question 15

Which of the following is not one of Hückel's criteria for aromaticity?

A)The compound must be cyclic
B)The compound must have one p-orbital on each atom of a ring
C)The compound must be planar or nearly planar so that there is a continuous overlap of p orbitals
D)The compound must have a closed loop of six pi electrons

Question 16

What is the IUPAC name of the following compound?

A)2-nitro-6-carboxybromobenzene
B)2-bromo-1-nitro-4-benzoic acid
C)2-bromo-4-carboxynitrobenzene
D)3-bromo-4-nitrobenzoic acid

Question 17

Which of the following statements is not true about the structure of benzene?

A)the carbon-carbon bonds are all the same length
B)the structure rapidly transforms between two resonance contributors
C)the structure is an average of two resonance contributors
D)the ring of six carbon atoms is planar

Question 18

Which orbitals contain the lone pairs on the nitrogen atoms labeled i and ii in the imidazole ring?

A)i = sp^2;; ii = sp³
B)i = p^;; ii = sp3
C)i = p^;; ii = sp³
D)i = p^;; ii = sp²

Question 19

Which orbital contains the lone pair on the nitrogen atom of pyridine?

A)s
B)p
C)sp
D)sp²

Question 20

What is the approximate length of the carbon-carbon bonds in benzene?

A)110 pm
B)121 pm
C)139 pm
D)156 pm

Question 21

Which of the following has the compounds shown in the correct order of decreasing acidity (i.e., more acidic > less acidic)?

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

Question 22

What is the best choice of reagent to achieve the following reaction?

A)Br₂, CCl₄
B)HBr, H₂O
C)Br₂, light
D)NaBr

Question 23

Which of the following compounds is antiaromatic?

A)ethane
B)cyclobutadiene
C)benzene
D)cyclooctatetraene

Question 24

Which of the following ions is aromatic?

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

Question 25

Which of the following has the compounds shown in the correct order of decreasing acidity (i.e., more acidic > less acidic)?

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

Question 26

Which of the following has the compounds shown in the correct order of decreasing acidity (i.e., more acidic > less acidic)?

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

Question 27

What is the major organic product obtained from the following reaction?

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

Question 28

Which of the following heterocycles is not aromatic?

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

Question 29

What is the major organic product obtained from the following reaction?

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

Question 30

What is the best choice of reagent to achieve the following reaction?

A)H₂SO₄
B)NaOH, H₂O
C)K₂Cr₂O₇, H₂SO₄
D)LiAlH₄

Question 31

Which of the following molecules is the most acidic?

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

Question 32

What is the major organic product obtained from the following reaction?

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

Question 33

Which of the following represents the energy levels of the molecular orbitals of cyclopentadienyl anion?

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

Question 34

Which of the following has the compounds shown in the correct order of decreasing acidity (i.e., more acidic > less acidic)?

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

Question 35

What is the best choice of reagent to achieve the following reaction?

A)H₂SO₄
B)NaOH, H₂O
C)K₂Cr₂O₇, H₂SO₄
D)H₂/Pd

Question 36

What is the major organic product obtained from the following reaction?

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

Question 37

What is the major organic product obtained from the following reaction?

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

Question 38

Which of the following compounds undergoes heterolytic carbon-halogen bond cleavage to form a stable organic cation?

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

Question 39

Which of the following has the compounds shown in the correct order of decreasing acidity (i.e., more acidic > less acidic)?

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

Question 40

What is the major organic product obtained from the following reaction?

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

Question 41

The following compound is named (Z)-2,3-diphenyl-2-hexene.

Question 42

Which of the following represents the energy levels of the molecular orbitals of cyclobutadiene?

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

Question 43

What are the relative positions of the substituents in the following structure?

A)anti
B)meta
C)ortho
D)para

Question 44

What are the relative positions of the substituents in the following structure?

A)anti
B)meta
C)ortho
D)para

Question 45

Furan has the structure shown below. The $\pi$ orbitals in furan are shown below.

Question 46

The product of the following reaction would be a dicarboxylic acid.

Question 47

Consider the following structures, A B
Structure A is more acidic than B.

Question 48

Consider the following structure. The ¹H NMR spectrum of this compound -60 ^$\circ$ C shows a peak at 7.6 ppm, this would indicate aromaticity.

Question 49

The product of the following reaction would be 1-bromo-1-phenylethane.

Question 50

What are the relative positions of the substituents in the following structure?

A)anti
B)meta
C)ortho
D)para

Question 51

The following compound should be name as 1-((1S, 3R)-3-methylcyclohexyl)benzene.

Question 52

How many p orbital electrons are present in cyclopentadienyl anion?

A)4
B)6
C)7
D)8

Question 53

Which of the following is not true about [the bridged [10]annulene shown below?

A)all of the carbon atoms of bridged [10]annulene are all in the same plane
B)bridged [10]annulene is aromatic
C)bridged [10]annulene undergoes substitution reactions similar to benzene
D)bridged [10]annulene has 10 pi electrons

Question 54

Which of the following does not undergo oxidation in the presence of H₂CrO₄?

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

Question 55

Which of the following is not true about [18]annulene?

A)[18]annulene is planar
B)[18]annulene is aromatic
C)[18]annulene gives one peak in the ¹H NMR spectrum
D)[18]annulene has 18 pi bonds

Question 56

What is the intermediate in the reaction of ethylbenzene with NBS in the presence of benzoyl peroxide to give 1-bromo-1-phenylethane?

A)Benzylic anion
B)Benzylic cation
C)Benzylic radical
D)Benzylic carbene

Question 57

How many p orbital electrons are present in furan?

A)4
B)6
C)7
D)8

Question 58

Phenols are stronger acids than alcohols because of the resonance stabilization of alkoxide ions.

Question 59

Which of the following is not true about cyclooctatetraene?

A)The planar conformation is antiaromatic
B)In the planar conformation there are two electrons in degenerate nonbonding pi orbitals.
C)In the tub conformation the pi system is not conjugated
D)The tub conformation is aromatic

Question 60

Which of the following is true about [10]annulene?

A)[10]annulene is planar
B)[10]annulene is nonaromatic
C)[10]annulene undergoes addition reactions similar to simple alkenes
D)[10]annulene has 10 pi electrons

Question 61

The following compound could be produced by reaction of phenol with bromobenzene.

Question 62

What is the major organic product obtained from the following reaction?

Question 63

Consider the following structure.
If named as an annulene, the name would be [ __ ] annulene.

Question 64

Consider the following structure. The ¹H NMR spectrum of [14]annulene at -60 ^$\circ$ C shows two peaks, one at 0 ppm and one at 7.6 ppm.

-The NMR data would seem to indicate that this compound is ____________.

Question 65

Consider the following structure.

-This structure contains ____ $\pi$ electrons.

Question 66

Consider the following general structure. Positions 1,4 and 2,6 and 3,5 are termed para, ortho, and meta, respectively.

Question 67

Answer the following questions concerning sulfathiazole below by filling ieach blank with the appropriate response.
The hybridization of the nitrogen atom in sulfathiazole is ______.
A. sp
B. sp²
C. sp³

Question 68

Answer the following questions concerning sulfathiazole below by filling ieach blank with the appropriate response.
According to Hückel criteria, sulfathiazole is predicted to be ___________.

Question 69

Consider the cycloheptatrienyl anion. Complete the following questions by filling in the blank with the appropriate word.
Consider the following compound. When treated with acidic K₂Cr₂O₇ the product would be classified as a ___________.

Question 70

Consider the following structure.
Using the Hückel criteria, the compound would be ______________.

Question 71

What is the IUPAC name of the following compound?

Question 72

Consider the cycloheptatrienyl anion. Complete the following questions by filling in the blank with the appropriate word.

-This anion has______ $\pi$ electrons.

Question 73

What is the major organic product obtained from the following reaction?

Question 74

Consider the cycloheptatrienyl anion. Complete the following questions by filling in the blank with the appropriate word.
Consider the following two compounds. A B
An ether solution containing these two substances was mixed with an aqueous 1 M NaOH solution. Substance _____ will be found in the basic layer.

Question 75

Consider the cycloheptatrienyl anion. Complete the following questions by filling in the blank with the appropriate word.
According the Hückel criteria this anion would be classified as ______________.

Question 76

What is the IUPAC name of the following compound?

Question 77

Consider the following structure. The ¹H NMR spectrum of [14]annulene at -60 ^$\circ$ C shows two peaks, one at 0 ppm and one at 7.6 ppm.

-The ratio of peak areas, respectively for the 7.6 ppm and 0 ppm, peaks would be_______.

Question 78

Answer the following questions concerning sulfathiazole below by filling ieach blank with the appropriate response.

-Assuming that the sulfur atom is sp²-hybridized, there are _____ $\pi$ -electrons in the sulfathiazole ring.

Question 79

What is the IUPAC name of the following compound?

Question 80

What is the IUPAC name of the following compound?