Aromatic Compounds: Structure, Properties, and Reactions

Question 1

Which of the following compounds meets the criteria to be considered aromatic?

Accepted Answer

Benzene

Answer

Cyclohexane

Answer

Ethene

Answer

Propane

Question 2

Which of the following reactions is characteristic of aromatic compounds?

Accepted Answer

Substitution

Answer

Addition

Answer

Elimination

Answer

Polymerization

Question 3

Which of the following functional groups, when attached to a benzene ring, is a strong electron-withdrawing group?

Accepted Answer

-COOH

Answer

-CH3

Answer

-OH

Answer

-NH2

Question 4

What is the IUPAC name for the compound with the molecular formula C6H5CH2Br?

Accepted Answer

Benzyl bromide

Answer

Phenylethyl bromide

Answer

Bromomethylbenzene

Answer

2-Bromoethylbenzene

Question 5

Which of the following statements about aromatic compounds is accurate?

Accepted Answer

They have a planar and cyclic structure.

Answer

They have sp3 hybridized carbon atoms.

Answer

They readily undergo addition reactions.

Answer

They have a strong odor.

Question 6

What is a defining characteristic of an electrophilic aromatic substitution reaction?

Accepted Answer

An electrophile attacks the aromatic ring, initiating the reaction.

Answer

A free radical intermediate forms during the reaction.

Answer

The reaction leads to the loss of aromaticity.

Question 7

Which of the following reactions is a characteristic electrophilic aromatic substitution reaction?

Accepted Answer

Nitration

Answer

Addition

Answer

Polymerization

Answer

Oxidation

Question 8

What is the major product of the following reaction: C6H5CH3 + KMnO4 → ?

Accepted Answer

Benzoic acid

Answer

Benzene

Answer

Methyl benzoate

Answer

Benzaldehyde

Question 9

Which of the following compounds exhibits resonance?

Accepted Answer

Benzene

Answer

Ethene

Answer

Propane

Answer

Methane

Question 10

What is the purpose of using a Lewis acid catalyst in electrophilic aromatic substitution reactions?

Accepted Answer

To activate the electrophile

Answer

To deactivate the nucleophile

Answer

To increase the rate of the reaction

Answer

To prevent side reactions

Question 11

What is the major product of the nitration of toluene?

Accepted Answer

2-nitrotoluene

Answer

3-nitrotoluene

Answer

4-nitrotoluene

Question 12

Which reaction is characteristic of compounds with an aromatic ring?

Accepted Answer

Electrophilic substitution

Answer

Electrophilic addition

Answer

Nucleophilic addition

Answer

Nucleophilic substitution

Question 13

Identify the compound that is classified as an aromatic hydrocarbon.

Accepted Answer

Naphthalene

Answer

Ethene

Answer

Propane

Answer

Ethanol

Question 14

What is the characteristic shape adopted by an aromatic ring?

Accepted Answer

Trigonal planar

Answer

Linear

Answer

Tetrahedral

Answer

Square pyramid

Question 15

Identify the reaction that exemplifies an electrophilic aromatic substitution reaction.

Accepted Answer

Nitration

Answer

Addition of hydrogen

Answer

Oxidation

Answer

Polymerisation

Question 16

In the reaction between benzene and chlorine in the presence of an iron catalyst, what is the major product formed?

Accepted Answer

Chlorobenzene

Answer

Dichlorobenzene

Answer

Trichlorobenzene

Answer

Benzene chloride

Question 17

What is the primary role of a catalyst in electrophilic aromatic substitution reactions?

Accepted Answer

To decrease the energy of the transition state

Answer

To increase the rate of reaction

Answer

To provide a nucleophile

Answer

To remove a leaving group

Question 18

Which of the following is a defining property of aromatic compounds?

Accepted Answer

Planar structure

Answer

High reactivity

Answer

Solubility in water

Answer

Low boiling point

Question 19

What is the molecular formula for benzene?

Accepted Answer

C6H6

Answer

C6H12

Answer

C6H14

Answer

C6H8

Question 20

Which of the following is an example of a benzene derivative?

Accepted Answer

Toluene

Answer

Ethane

Answer

Methane

Answer

Propane

Question 21

Which of the following is classified as an electrophile?

Accepted Answer

Nitric acid

Answer

Benzene

Answer

Toluene

Answer

Sodium hydroxide

Question 22

What is the major product formed when benzene reacts with chlorine in the presence of a Lewis acid?

Accepted Answer

Chlorobenzene

Answer

Dichlorobenzenes

Answer

Benzene chloride

Answer

Trichlorobenzenes

Question 23

What is the name of the process by which aromatic compounds can lose their aromatic character?

Accepted Answer

Hydrogenation

Answer

Dehydrogenation

Answer

Alkylation

Answer

Acylation

Question 24

In aromatic compounds, what does resonance refer to?

Accepted Answer

The spreading of electrons across multiple atoms, resulting in multiple valid Lewis structures

Answer

A single, unchanging Lewis structure for the molecule

Answer

A type of isomerism where compounds have different structures but the same molecular formula

Question 25

Which of the following reactions is a characteristic of aromatic compounds?

Accepted Answer

Electrophilic substitution

Answer

Electrophilic addition

Answer

Nucleophilic addition

Answer

Free radical substitution

Question 26

What is the name of the six-membered heterocyclic aromatic compound containing one nitrogen atom?

Accepted Answer

Pyridine

Answer

Pyrimidine

Answer

Piperidine

Answer

Quinoline

Question 27

Which of the following statements about the Huckel rule is accurate?

Accepted Answer

It is a necessary but not sufficient condition for aromaticity.

Answer

It applies only to monocyclic compounds.

Answer

It states that a compound must have 4n+2 pi electrons to be aromatic.

Answer

It is only applicable to benzenoid compounds.

Question 28

In the benzene ring, what is the hybridization state of the carbon atoms, and how does this contribute to the molecule's stability?

Accepted Answer

sp2 hybridization, forming three sigma bonds and one pi bond

Answer

sp3 hybridization, forming four sigma bonds

Answer

sp hybridization, forming two sigma bonds and two pi bonds

Answer

sp2 hybridization, forming two sigma bonds and one pi bond

Question 29

Which compound satisfies the Hückel criteria for aromaticity?

Accepted Answer

Benzene

Answer

Cycloheptatriene

Answer

Cyclopentene

Answer

Cyclohexadiene

Question 30

What is the major product of the electrophilic aromatic substitution reaction of benzene with NO₂⁺?

Accepted Answer

Nitrobenzene

Answer

Benzene-1,4-diol

Answer

Benzene-1,2-diol

Answer

Phenol

Question 31

Which reagent is used to reduce benzene to cyclohexane?

Accepted Answer

H2, Pd/C

Answer

LiAlH4

Answer

KMnO4

Answer

NaBH4

Question 32

Which compound is more reactive in electrophilic aromatic substitution reactions?

Accepted Answer

Toluene

Answer

Benzoic acid

Answer

Benzene

Answer

Nitrobenzene

Question 33

What is the hybridization of the carbon atoms in the benzene ring?

Accepted Answer

sp2

Answer

sp

Answer

sp3

Question 34

What is the major product of the Friedel-Crafts acylation reaction between benzene and acetyl chloride?

Accepted Answer

Acetophenone

Answer

Benzaldehyde

Answer

Benzoic acid

Answer

Phenyl acetate

Question 35

What is the molecular formula of benzene, an aromatic hydrocarbon with a characteristic ring structure?

Accepted Answer

C6H6

Answer

C8H8

Answer

C7H7

Answer

C5H5

Question 36

Which of the following properties is characteristic of aromatic compounds?

Accepted Answer

They undergo electrophilic substitution reactions

Answer

They have a low boiling point

Answer

They are highly reactive with oxygen

Answer

They are soluble in water

Question 37

In the nitration reaction of benzene, which reagent combination is commonly used to introduce a nitro group (-NO2) into the benzene ring?

Accepted Answer

Nitric acid (HNO3) and sulfuric acid (H2SO4)

Answer

Hydrochloric acid (HCl) and zinc (Zn)

Answer

Potassium permanganate (KMnO4) and water (H2O)

Answer

Sodium hydroxide (NaOH) and water (H2O)

Question 38

What is the major organic product formed when benzene reacts with concentrated sulfuric acid (H2SO4) under appropriate conditions?

Accepted Answer

Benzenesulfonic acid

Answer

Cumene

Answer

Ethylbenzene

Answer

Nitrobenzene

Question 39

Which of the following diagrams represents a valid resonance structure of the benzene molecule?

Accepted Answer

Image of benzene resonance structure 1

Answer

Image of cyclohexane

Answer

Image of propene

Answer

Image of ethene

Question 40

What type of hybridization do the carbon atoms in the benzene ring exhibit?

Accepted Answer

sp2

Answer

sp3

Answer

sp3d

Answer

sp

Question 41

When benzene reacts with chlorine (Cl2) in the presence of a Lewis acid catalyst, the major organic product formed is:

Accepted Answer

Chlorobenzene

Answer

Trichlorobenzene

Answer

Tetrachlorobenzene

Answer

Dichlorobenzene

Question 42

Which statement best describes the structure of benzene?

Accepted Answer

A flat, ring-shaped molecule with six carbon atoms and six delocalized electrons.

Answer

A three-dimensional structure with alternating single and double bonds.

Answer

A linear molecule with alternating single and double bonds.

Question 43

Which of the following is NOT a characteristic of aromatic compounds?

Accepted Answer

They readily undergo addition reactions.

Answer

They are relatively stable.

Answer

They have a delocalized pi electron system.

Answer

They exhibit a planar, cyclic structure.

Question 44

When benzene reacts with nitric acid in the presence of sulfuric acid, what is the main product formed?

Accepted Answer

Nitrobenzene

Answer

Toluene

Answer

Phenol

Answer

Aniline

Question 45

What is the main reason for benzene's stability?

Accepted Answer

The delocalization of pi electrons across the ring.

Answer

The strong C-H bonds in the molecule.

Answer

The presence of alternating single and double bonds.

Answer

The planar structure of the molecule.

Question 46

Which of these is NOT an aromatic compound?

Accepted Answer

Cyclohexene

Answer

Phenol

Answer

Naphthalene

Answer

Pyridine

Question 47

What compound is formed when benzene reacts with a mixture of concentrated nitric acid and concentrated sulfuric acid?

Accepted Answer

Nitrobenzene

Answer

Aniline

Answer

Toluene

Answer

Phenol

Question 48

Which of the following is a major application of aromatic compounds?

Accepted Answer

Production of plastics and polymers.

Answer

Production of soaps and detergents.

Answer

Manufacture of fertilizers.

Answer

Production of paper and pulp.