Free Benzene and Aromatic Compounds MCQs with Answers
172 Benzene and Aromatic Compounds MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Benzene has a planar ring of delocalised π electrons, giving aromatic stability and equal carbon-carbon bond lengths. The topic covers resonance, electrophilic substitution reactions such as nitration, halogenation, sulphonation and Friedel-Crafts reactions, along with substituent effects and the distinction between substitution in benzene and addition in ordinary alkenes.
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172 questions · page 6 of 9
- A. Alkylation
- B. Halogenation
- C. Nitration
- D. Acylation
Explanation: Acetophenone is formed by friedal craft acylation. This reaction involves acylation of benzene with acyl chloride or acyl anhydride
Correct answer: Acylation- A. HSO4-
- B. H2SO4
- C. SO3
- D. HSO3
Explanation: SO3 acts as an electrophile in sulphonation. Sometimes H2SO4 is also seen in equations in place of SO3 because H2SO4 dissociates to give…
Correct answer: SO3- A. Good electrophile
- B. Good nucleophile
- C. Resonance hybrid
- D. Extraordinary stable
Explanation: Benzene is a nucleophile because of its delocalized electrons thus the molecule has electron-rich areas which are frequently attacked by…
Correct answer: Good nucleophile- A. In alkynes to identify the position of triple bond
- B. In arenes to identify the position first substitution
- C. In arenes to identify the position second substituition
- D. In all hydrocarbons to identify the position of functional group
Explanation: Ortho, para, and meta are prefixes used to designate the relative positions of second substituent groups on an aromatic ring in organic…
Correct answer: In arenes to identify the position second substituition105. When the two substitutions are different in arenes, they are put in which of the following order?
- A. Numerically
- B. Alphabetically
- C. Alphanumerically
- D. None of these options is correct
Explanation: The substituents in arenes are put in alphabetical order when they are different.
Correct answer: Alphabetically- A. Low melting and low boiling points
- B. High melting and high boiling points
- C. Low melting and high boiling points
- D. High solubility in polar solvents
Explanation: OPTION A: Arenes are compounds that contain benzene ring(s). Since the only possible intermolecular force of attraction, in this case, are…
Correct answer: Low melting and low boiling points- A. Elimination
- B. Addition
- C. Substitution
- D. Hydrogenation
Explanation: Option A: There is no such evidence of elimination reaction in Benzene since it completely destroys the stability of Benzene.Addition…
Correct answer: Elimination- A. Hydrogenation
- B. Dehydrogenation
- C. Dehydration
- D. None of these options are correct
Explanation: Dehydrogenation is the process by which hydrogen is removed from an organic compound to form a new chemical (e.g., to convert saturated…
Correct answer: Dehydrogenation- A. Benzene reactivity
- B. That benzene has dual character
- C. That benzene has less heat of formation
- D. All of these options are correct
Explanation: Kekule's structure does not explain the extra ordinary stable nature of benzene molecule and its lack of reactivity towards addition…
Correct answer: All of these options are correct- A. Tetrahedral
- B. Hexagonal planar
- C. Hexagonal irregular
- D. Trigonal planar
Explanation: A benzene ring has 6 carbons hence it is a hexagon and it is hexagonal planar and not hexagonal irregular because all the carbons are in…
Correct answer: Hexagonal planar- A. FeBr3
- B. FeCl4-
- C. Cl+
- D. Cl-
Explanation: Electrophiles are species with a positive charge. The only element/molecule with a positive charge is Cl hence, Option C is the correct…
Correct answer: Cl+- A. Hexagonal planar
- B. Square planar
- C. Trigonal planar
- D. Linear
Explanation: Benzene has 6 carbons, hence it is given the name hexagon. All the carbons are in the same planar hence it is called planar.
Correct answer: Hexagonal planar- A. KMnO4
- B. K2Cr2O7
- C. KHMnO4
- D. V2O5
Explanation: Vanadium pentoxide (V2O5) can be used as an oxidizing agent to oxidize benzene and its derivatives under specific conditions.
Correct answer: V2O5- A. Two
- B. One
- C. Three
- D. None of these
Explanation: Benzene can form only one type of monosubstituted means that it cannot form different atoms just by replacing the position of the attached…
Correct answer: One- A. Pyrrole
- B. Furan
- C. Thiophene
- D. All
Explanation: In benzene derivatives, all the atoms that make up the ring are carbon atoms.
Correct answer: All- A. Increases electron density
- B. Decrease electron density on benzene
- C. Make benzene less reactive
- D. None of these
Explanation: The electron donating group such as the alkyl group donates electrons to the benzene ring and hence increases the density.
Correct answer: Increases electron density- A. Elimination
- B. Addition
- C. Substitution
- D. Dehydration
Explanation: There is no such evidence of an elimination reaction in Benzene since it completely destroys its stability.Benzene generally also resists…
Correct answer: Elimination- A. Ortho-xylene
- B. Para-xylene
- C. Para-methyl toluene
- D. Meta-methyl toluene
Explanation: Xylene is any of three organic compounds with the formula (CH3)2C6H4. They are derived from the substitution of two hydrogen atoms with…
Correct answer: Para-xylene- A. Alkyl group
- B. Benzyl group
- C. Phenyl group
- D. Ethyl group
Explanation: Reason: A benzene ring has the formula of C6H6. When a hydrogen atom is removed, this becomes C6H5. C6H5 is known as a phenyl group.
Correct answer: Phenyl group- A. Highly saturated
- B. Highly unsaturated
- C. Gives substitution reactions
- D. Gives elimination reactions
Explanation: Option B. Kekule formula with three double bonds demands a high degree of unsaturation from benzene while usually it exhibits a saturated…
Correct answer: Highly unsaturated