Haloalkanes and Haloarenes JEE Main PYQs (2020–2026)

Solved Haloalkanes and Haloarenes PYQs

3 recent questions with answers. The full set of 138 is free to practise.

1. JEE Main 2026EasyNucleophilic Substitution Reactions of Haloalkanes (SN1 and SN2)
   Q1

   Given below are two statements :
   
   Statement (I) : Benzyl chloride reacts faster in $S_{N}1$ mechanism than ethyl chloride.
   
   Statement (II) : Ethyl carbocation intermediate is less stabilized by hyperconjugation than benzyl carbocation by resonance.
   
   In the light of the above statements, choose the correct answer from the options given below :

   • ABoth Statement I and Statement II are true
   • BBoth Statement I and Statement II are false
   • CStatement I is true but Statement II is false
   • DStatement I is false but Statement II is true

   Show answer & solution

   Correct answer: (A)

   In an $S_{N}1$ reaction, the rate depends on the stability of the carbocation formed after the leaving group departs.
   
   For benzyl chloride:
   
   $${\text{C}}_6{\text{H}}_5{\text{CH}}_2\text{Cl}\to {\text{C}}_6{\text{H}}_5{\text{CH}}_2^{+}+{\text{Cl}}^{-}$$
   
   The benzyl carbocation formed is highly stable because the positive charge is delocalised over the benzene ring by resonance.
   
   For ethyl chloride:
   
   $${\text{CH}}_3{\text{CH}}_2\text{Cl}\to {\text{CH}}_3{\text{CH}}_2^{+}+{\text{Cl}}^{-}$$
   
   The ethyl carbocation is much less stable. It gets only slight stabilization by hyperconjugation, which is weaker than resonance stabilization.
   
   So:
   
   Statement (I) is true: benzyl chloride reacts faster than ethyl chloride in the $S_{N}1$ mechanism.
   
   Statement (II) is also true: ethyl carbocation is less stabilized by hyperconjugation than benzyl carbocation by resonance.
   
   Also, Statement (II) correctly explains Statement (I).
   
   Therefore, the correct answer is:
   
   $$\boxed{\text{Option A}}$$
2. JEE Main 2026MediumNucleophilic Aromatic Substitution in Haloarenes
   Q2

   As compared with chlorocyclohexane, which of the following statements correctly apply to chlorobenzene?
   
   A. The magnitude of negative charge is more on chlorine atom.
   
   B. The $C-Cl$ bond has partial double bond character.
   
   C. $C-Cl$ bond is less polar.
   
   D. $C-Cl$ bond is longer due to repulsion between delocalised electrons of the aromatic ring and lone pairs of electrons of chlorine.
   
   E. The $C-Cl$ bond is formed using ${sp}^2$ hybridised orbital of carbon.
   
   Choose the correct answer from the options given below :

   • AB, C and E Only
   • BA, C and E Only
   • CB, C and D Only
   • DA, D and E Only

   Show answer & solution

   Correct answer: (A)

   In chlorocyclohexane, chlorine shows only the $-I$ (electron-withdrawing inductive) effect.
   
   So, the $C-Cl$ bond remains a normal single bond and is more polar (more electron density is pulled towards chlorine).
   
   In chlorobenzene, chlorine shows two effects: $-I$ and $+M$ (lone pair donation by resonance into the benzene ring).
   
   Because $-I>+M$, the bond is still polar, but the $+M$ effect reduces the polarity compared to chlorocyclohexane.
   
   The $+M$ effect also causes resonance between chlorine lone pairs and the aromatic ring, which gives the $C-Cl$ bond partial double bond character.
3. JEE Main 2023EasyClassification, Nomenclature & Physical Properties of Haloalkanes and Haloarenes
   Q3

   The pair from the following pairs having both compounds with net non-zero dipole moment is

   • Acis-butene, trans-butene
   • BCH ${}_2$ Cl ${}_2$ , CHCl ${}_3$
   • CBenzene, anisidine
   • D1,4-Dichlorobenzene, 1,3-Dichlorobenzene

   Show answer & solution

   Correct answer: (B)

   The correct option from the pairs having both compounds with a net non-zero dipole moment is:
   
   Option A: $\text{cis-butene, trans-butene}$ -butene has a net dipole moment because the two alkyl groups are on the same side of the molecule, causing an imbalance in the distribution of electrons. However, trans-butene is symmetric, so the dipole moments of the two alkyl groups cancel each other out, giving it a net dipole moment of zero. Therefore, this pair does not have both compounds with a net non-zero dipole moment.
   
   Option B: ${\text{CH}}_2{\text{Cl}}_2,{\text{CHCl}}_3$ ${\text{CH}}_2{\text{Cl}}_2$ (dichloromethane) and ${\text{CHCl}}_3$ (chloroform) have a net non-zero dipole moment due to the difference in electronegativity between the hydrogen and chlorine atoms. Hence, this pair has both compounds with a net non-zero dipole moment.
   
   Option C: $\text{Benzene, Anisidine}$ has a symmetrical structure, leading to a net zero dipole moment. Anisidine, however, does have a net dipole moment due to the asymmetry in its structure. Therefore, this pair does not have both compounds with a net non-zero dipole moment.
   
   Option D: $\text{1,4-Dichlorobenzene, 1,3-Dichlorobenzene}$
   
   $\text{1,4-Dichlorobenzene}$ has a symmetrical structure, leading to a net zero dipole moment. However, $\text{1,3-Dichlorobenzene}$ has a non-zero dipole moment due to the asymmetry in its structure. Therefore, this pair does not have both compounds with a net non-zero dipole moment.

Topic-wise question count

Where JEE Main has asked from Haloalkanes and Haloarenes, most frequent first.

• Nucleophilic Substitution Reactions of Haloalkanes (SN1 and SN2)54
• Methods of Preparation of Haloalkanes and Haloarenes27
• Elimination Reactions of Haloalkanes (E1 and E2)25
• Classification, Nomenclature & Physical Properties of Haloalkanes and Haloarenes8
• Electrophilic Substitution Reactions of Haloarenes8
• Nucleophilic Aromatic Substitution in Haloarenes7
• Reactions with Metals (Grignard Reagent, Wurtz, Fittig)6
• Polyhalogen Compounds (Chloroform, Iodoform, Freons, DDT)3

Year-wise Haloalkanes and Haloarenes questions in JEE Main

Number of questions from this chapter in each year's paper(s).