MCQMediumJEE 2026Reaction Mechanisms (Substitution, Addition, Elimination)

JEE Chemistry 2026 Question with Solution

Given below are two statements:

Statement I: C–Cl bond is stronger in CH2=CHCl\mathrm{CH_2 = CH{-}Cl} than in CH3CH2Cl\mathrm{CH_3{-}CH_2{-}Cl}.

Statement II: The given optically active molecule, on hydrolysis, gives a solution that can rotate the plane polarized light.

In the light of the above statements, choose the correct answer from the options given below:

  • A

    Both Statement I and Statement II are false

  • B

    Statement I is true but Statement II is false

  • C

    Both Statement I and Statement II are true

  • D

    Statement I is false but Statement II is true

Answer

Correct answer:C

Step-by-step solution

Standard Method

Given: Two statements are to be checked for correctness.

Find: Which option correctly identifies the truth values of Statement I and Statement II.

Statement I: In vinyl chloride (CH2=CHCl)\mathrm{(CH_2=CH{-}Cl)}, the carbon bonded to chlorine is sp2sp^2 hybridized. The C–Cl bond has partial double bond character due to resonance, so this bond is stronger than the C–Cl bond in ethyl chloride (CH3CH2Cl)\mathrm{(CH_3{-}CH_2{-}Cl)}, where the carbon is sp3sp^3 hybridized.

Therefore, Statement I is true.

Statement II: The given molecule is optically active. On hydrolysis, substitution occurs without destroying chirality, so a chiral alcohol is formed. Hence, the resulting solution remains optically active and can rotate plane polarized light.

Therefore, Statement II is true.

So, both Statement I and Statement II are true. The correct option is C.

Stepwise Explanation

Given:

  • Statement I compares the strength of the C–Cl bond in CH2=CHCl\mathrm{CH_2=CH{-}Cl} and CH3CH2Cl\mathrm{CH_3{-}CH_2{-}Cl}.
  • Statement II asks whether hydrolysis of the given optically active molecule gives a solution that can rotate plane polarized light.

Find: The correct option.

  1. Analyse Statement I

In vinyl chloride CH2=CHCl\mathrm{CH_2=CH{-}Cl}, the chlorine atom is attached to an sp2sp^2 hybridized carbon.

Because of resonance, the C–Cl bond acquires partial double bond character.

This makes the bond shorter and stronger than the C–Cl bond in ethyl chloride CH3CH2Cl\mathrm{CH_3{-}CH_2{-}Cl}, where chlorine is attached to an sp3sp^3 hybridized carbon.

So, Statement I is true.

  1. Analyse Statement II

The molecule is stated to be optically active.

On hydrolysis, substitution gives a chiral alcohol without loss of chirality.

Therefore, the product solution remains optically active and can rotate plane polarized light.

So, Statement II is true.

  1. Conclude

Both statements are true.

Hence, the correct option is C, that is, option (3).

Common mistakes

  • Assuming every C–Cl bond has the same strength is incorrect. In vinyl chloride, resonance gives the bond partial double bond character. Always check hybridization and resonance before comparing bond strength.

  • Thinking that hydrolysis always destroys optical activity is incorrect. Optical activity is lost only if chirality is destroyed or racemization occurs. Here, the solution indicates chirality is preserved after substitution.

  • Focusing only on the presence of chlorine and ignoring the carbon environment is incorrect. The difference between sp2sp^2 and sp3sp^3 bonded carbon is essential for Statement I.

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