Haloalkanes and Haloarenes JEE Main previous year questions with solutions

5 solved JEE Main questions on Haloalkanes and Haloarenes, free to read — no sign-in needed. The full chapter has 194 questions; sign in to attempt the remaining 189 in the exam simulator.

1. Q1JEE Main 2026 (05 Apr, Shift 2)Grignard Reagent
   $RMgI$ when treated with ice cold water liberated a gas which occupied $1.4\text{ dm}^3/\text{g}$ at STP. The gas produced is further reacted with iodine in presence of $HIO_3$ to give compound (X). Compound (X) in presence of Na and dry ether produced compound (Y). Molar mass of compound (Y) is _______ $\text{g mol}^{-1}$. (Nearest integer)
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   Answer: 30

   The reaction of Grignard reagent with water yields an alkane: $RMgI + H_2O \rightarrow RH + Mg(OH)I$ Given that $1 \text{ g}$ of the gas $RH$ occupies $1.4 \text{ dm}^3$ at STP, we can find its molar mass. Using the standard molar volume at STP ($22.4 \text{ dm}^3$): $\text{Molar mass of } RH = \dfrac{22.4 \text{ dm}^3 \text{ mol}^{-1}}{1.4 \text{ dm}^3 \text{ g}^{-1}} = 16 \text{ g mol}^{-1}$ The alkane with a molar mass of $16 \text{ g mol}^{-1}$ is methane ($CH_4$). Methane reacts with iodine in the presence of an oxidizing agent like $HIO_3$ (which prevents the backward reaction by consuming the formed $HI$) to give methyl iodide: $CH_4 + I_2 \xrightarrow{HIO_3} CH_3I + HI$ Thus, compound (X) is methyl iodide ($CH_3I$). Compound (X) undergoes the Wurtz reaction when treated with sodium and dry ether to form a higher alkane: $2CH_3I + 2Na \xrightarrow{\text{dry ether}} CH_3-CH_3 + 2NaI$ Compound (Y) is ethane ($C_2H_6$). The molar mass of ethane ($C_2H_6$) is: $2 \times 12 + 6 \times 1 = 30 \text{ g mol}^{-1}$ Answer: $30$
2. Q2JEE Main 2025 (22 Jan, Shift 2)Preparation and Properties of Monohalides
   The compound with molecular formula $\mathrm{C}_6 \mathrm{H}_6$, which gives only one monobromo derivative and takes up four moles of hydrogen per mole for complete hydrogenation has ________ $=$ electrons.
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   Answer: 8

   Since 4 moles of $\mathrm{H}_2$ is being added for complete hydrogenation the degree of unsaturation $=4$ No. of $\pi$ electrons in $\mathrm{C}_6 \mathrm{H}_6=4 \times 2=8$
3. Q3JEE Main 2023 (31 Jan, Shift 2)Preparation and Properties of Aryl Halides
   In the following halogenated organic compounds the one with maximum number of chlorine atoms in its structure is:
   1. A.Chloral
   2. B.Gammaxene
   3. C.Chloropicrin
   4. D.Freon-$12$
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   Answer: (B)

   Percentage of chlorine content = $\dfrac{\text{mass of chlorine}}{\text{mass of organic compound}}\times 100$ (A) Chloral $({CCl}_{3}CHO)$: Percentage of chlorine content = $\dfrac{3\times 35.5}{147.5}\times 100=72.203$ (B) Gammaxene $\left({C}_{6}{H}_{6}{Cl}_{6}\right)$: Percentage of chlorine content = $\dfrac{6\times 35.5}{291}\times 100=73.2$ (C) Chloropicrin ${Cl}_{3}C–{NO}_{2}$: Percentage of chlorine content = $\dfrac{3\times 35.5}{165}\times 100=64.54$ (D) Freon-$12$ $\left({CF}_{2}{Cl}_{2}\right)$: Percentage of chlorine content = $\dfrac{2\times 35.5}{121}\times 100=58.67$ As per the percentage of chlorine, Gammaxene has the maximum number of chlorine atoms.
4. Q4JEE Main 2026 (22 Jan, Shift 1)Preparation and Properties of Aryl Halides
   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 $\mathrm{C}-\mathrm{Cl}$ bond has partial double bond character. C. $\mathrm{C}-\mathrm{Cl}$ bond is less polar. D. $\mathrm{C}-\mathrm{Cl}$ bond is longer due to repulsion between delocalised electrons of the aromatic ring and lone pairs of electrons of chlorine. E. The $\mathrm{C}-\mathrm{Cl}$ bond is formed using $\mathrm{sp}^{2}$ hybridised orbital of carbon. Choose the correct answer from the options given below:
   1. A.B, C and E Only
   2. B.A, C and E Only
   3. C.A, D and E Only
   4. D.B, C and D Only
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   Answer: (A)

   Chlorobenzene has Cl attached to an sp² carbon of the benzene ring, while chlorocyclohexane has Cl attached to an sp³ carbon. Statement B is correct: the C-Cl bond has partial double bond character due to resonance with the aromatic π system, where chlorine's lone pairs interact with the aromatic ring. Statement C is correct: the C-Cl bond is less polar in chlorobenzene because the resonance contribution reduces the electronegativity difference between C and Cl. Statement E is correct: the C-Cl bond is formed using sp² hybridized orbital of carbon. Statement A is incorrect because chlorine carries less negative charge due to resonance donation to the aromatic system. Statement D is incorrect because the C-Cl bond is actually shorter in chlorobenzene due to partial double bond character, not longer. The correct statements are B, C, and E only.
5. Q5JEE Main 2026 (08 Apr, Shift 2)Preparation and Properties of Monohalides
   Given below are two statements: Statement I: Due to increase in van der Waals forces, the order of boiling points is CH$_3$CH$_2$CH$_2$I > CH$_3$CH$_2$I > CH$_3$I. Statement II: As para-dichlorobenzene is more symmetric, its melting point is higher than ortho-dichlorobenzene, however its boiling point is lower than ortho-dichlorobenzene. In the light of the above statements, choose the correct answer from the options given below:
   1. A.Both Statement I and Statement II are true
   2. B.Both Statement I and Statement II are false
   3. C.Statement I is true but Statement II is false
   4. D.Statement I is false but Statement II is true
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   Answer: (A)

   Statement I is true because as the size of the alkyl group increases, the molecular mass and surface area increase. This leads to an increase in the magnitude of van der Waals forces, which in turn increases the boiling point. Thus, the correct order of boiling points is $\text{CH}_3\text{CH}_2\text{CH}_2\text{I} \gt \text{CH}_3\text{CH}_2\text{I} \gt \text{CH}_3\text{I}$. Statement II is true because para-dichlorobenzene is more symmetrical than ortho-dichlorobenzene, allowing it to pack more efficiently in the crystal lattice, which results in a higher melting point. However, ortho-dichlorobenzene has a higher dipole moment than para-dichlorobenzene (which has a dipole moment of zero). The stronger dipole-dipole interactions in ortho-dichlorobenzene lead to a higher boiling point compared to para-dichlorobenzene. Both Statement I and Statement II are true. Answer: Both Statement I and Statement II are true