CBSE 2024 · Region 2 · Set 1 · Q25 · 3 marks
Give reasons for the following :(a)Chlorine is ortho/para directing in electrophilic aromatic substitution reactions, though chlorine is an electron withdrawing group.(b)Racemic mixture is optically inactive.(c)Allyl chloride is hydrolysed more readily than n-propyl chloride.
Give reasons for the following :
(a)
Chlorine is ortho/para directing in electrophilic aromatic substitution reactions, though chlorine is an electron withdrawing group.
(b)
Racemic mixture is optically inactive.
(c)
Allyl chloride is hydrolysed more readily than n-propyl chloride.
Marking-scheme solution
(a)
Because of the stabilisation of intermediate carbocation through resonance. / Through resonance, chlorine tends to stabilize the carbocation and the effect is more pronounced at ortho- and para- positions.
(b)
Because mixture contains two enantiomers in equal proportions resulting in Zero Optical Rotation. / Due to the external compensation of equal percentage of (+) and (-) forms resulting in Zero Optical Rotation.
(c)
Because of the resonance stabilization of allyl carbocation.
Haloalkanes and HaloarenesNature of C–X BondUnderstandshort_answermedium
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CBSE Class 12 Chemistry past-paper question from the 2024board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.