All Free Chemistry MCQs with Answers

• 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…

• 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…

• 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…

• 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.

• 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.

• 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…

• A. Pyrrole
• B. Furan
• C. Thiophene
• D. All

Explanation: In benzene derivatives, all the atoms that make up the ring are carbon atoms.

• 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.

• 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…

• 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…

• 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.

• 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…

• A. Between the C-C bonds of benzene
• B. Above and below the carbon bonds
• C. In the form of cloud above and below the benzene ring
• D. None of these

Explanation: Benzene is a cyclic molecule in which all of the ring atoms are sp2-hybridized.

• A. Between the C-C bonds of benzene
• B. Above and below the carbon bonds
• C. In the form of a cloud above and below the benzene ring
• D. None of these options is correct

Explanation: All of the carbon atoms in the benzene rings are sp2-hybridized: the overlap of the sp2 orbitals around the ring produces a framework of…

• A. Increase electron density at the ortho and para positions
• B. Decrease electron density at the ortho and para positions
• C. Make benzene less reactive
• D. Both Options B and C are correct

Explanation: The meta groups deactivate the ring, by the inductive effect, in the presence of an electronegative atom, that withdraws the electrons…

• A. Anthracene
• B. Naphthalene
• C. Phenol
• D. None of these options is correct

Explanation: All of these compounds contain a benzene ring, hence all are aromatic.

• A. In alkynes to identify the position of the triple bond
• B. In arenes to identify the position of the first substitution
• C. In arenes to identify the position of the second substitution
• D. In all hydrocarbons to identify the position of the functional group

Explanation: The terms ortho, meta, and para are prefixes used in organic chemistry to indicate the position of non-hydrogen substituents on a…

• A. Three triple bonds
• B. Two double bonds
• C. Three double bonds
• D. No multiband

Explanation: Option C is correct since benzene is a hydrocarbon composed of six carbons connected via a covalent bond, and exists in the form of a…

• A. The two isomers of benzene
• B. The isomers of arenes
• C. The two-resonance structure of benzene
• D. The two-resonance structure of phenols

Explanation: This option is correct because kekule structure represents the resonating structure of benzene according to which benzene has a ring…

• A. Two double bonds
• B. Delocalized pi-electron charge
• C. Three double bonds
• D. One sigma bond

Explanation: Benzene has a delocalized pi-electron system. Its alternative double bonds cause the ring to become delocalized and constitute the…