250+ TOP MCQs on Haloalkanes Classification and Answers

Chemistry Multiple Choice Questions on “Haloalkanes Classification”.

1. Monohalo, dihalo, trihalo and tetrahalo are types of haloalkanes and haloarenes based on the ______
a) type of halogen atom
b) number of halogen atoms
c) nature of carbon atom
d) hybridisation of C atom to which halogen is bonded
Answer: b
Clarification: Haloalkanes may be classified as mono, di, tri, tetra and so on depending on the number of halogen atoms present in their structure.

2. A monohaloarene is an example of a/an __________
a) aliphatic halogen compound
b) aromatic halogen compound
c) alkyl halide
d) side chain substituted aryl halide
Answer: b
Clarification: A monohaloarene is a compound in which the halogen is directly attached to the benzene ring. Side chain substituted aryl halides are also aromatic halogen compounds with the halogen not directly attached to the benzene ring.

3. What is the general formula for haloalkanes? (X=halogen atom, n = 1, 2, 3…)
a) C_nH_2nX
b) C_nH_2n+1X
c) C_nH_2n-1X
d) C_nH_2n-3X
Answer: b
Clarification: The general formula for haloalkanes is C_nH_2n+1X where X is a halogen atom and n = 1, 2, 3… The formulae C_nH_2n-1X and C_nH_2n-3X are that of haloalkenes and haloalkynes respectively.

4. Which of the following compounds contains an allylic carbon?

a) A
b) B
c) C
d) D
Answer: a
Clarification: A sp³ hybridised C atom present adjacent to a C-C double bond is called an allylic carbon, and when the halogen atom is bonded to this carbon, it is called an allylic halide.

5. Which of the following categories does the compound shown belong to?

a) Primary haloalkane
b) Secondary haloalkane
c) Tertiary haloalkane
d) Haloarene
Answer: b
Clarification: The compound shown is cyclohexyl iodide, in which the halogen atom is bonded to an alkyl group that is alicyclic in nature. Since there are effectively two alkyl groups attached to the carbon bonded to the halogen atom, it is classified as secondary or 2° cyclo alkyl halide.

6. What is the nature of the circled C atom in the following compound?

a) sp² hybridised
b) allylic
c) benzylic
d) vinylic
Answer: c
Clarification: The circled C atom is sp³ hybridised and is attached directly to an aromatic ring, hence it is a benzylic carbon and the compound is a 1o benzylic halide.

7. In which of the following cases will the compound be a tertiary (3°) halogen compound? (X=halogen atom)

a) R’=R”=H
b) R’=CH₃, R”=H
c) R’=H, R”=CH₃
d) R’=R”=CH₃
Answer: d
Clarification: When R and R’ both are CH₃ groups, then the carbon atom bonded to the halogen will have three alkyl groups attached to it including the benzene ring.

8. Which of the following is a vinylic halide?
a) CH₂=CHCHCl₂
b) CH₃CHClCH₃
c) (CH₃)₂C=CHCH₂Cl
d) CH₃CH=CClCH₂CH₃
Answer: d
Clarification: In CH₃CH=CClCH₂CH₃, the Cl is bonded directly to the C atom of a C-C double bond, and hence it is a vinylic halide. CH₃CHClCH₃ is an alkyl halide whereas CH₂=CHCHCl₂ and (CH₃)₂C=CHCH₂Cl are allylic halides.

9. The compound C6H5F is an example of a ________ halide.
a) allylic
b) benzylic
c) vinylic
d) aryl
Answer: d
Clarification: In C₆H₅F, the F atom is directly attached to the sp² hybridised carbon atom of an aromatic ring, i.e., benzene.

10. The compound in which a CH₂Br group is attached to a benzene ring is an aryl halide.
a) True
b) False
Answer: b
Clarification: The Br atom is bonded to a carbon atom which is attached to sp² hybridised carbon of benzene. This is an example of a side chain substituted aryl halide.