9701 MCQ Solution 65

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Question 65: [Organic > Carbonyl Compounds]

Which reaction is not an electrophilic addition?

A CH₂=CH₂ + HI à CH₃CH₂I

B CH₃CH=CH₂ + Br₂ à CH₃CHBrCH₂Br

C CH₃CH=CH₂ + H₂O à CH₃CH(OH)CH₃

D CH₃CHO + HCN à CH₃CH(OH)CN

Note: in option C there is a catalyst - conc H₂SO₄

Reference: Past Exam Paper –June 2003 Paper 1 Q25

Solution 65:

Answer: D.

In organic reactions electrophilic addition occurs wherever a double bond is broken. In option A, a double bond is replaced with H and I atoms. In option B, the double bond is replaced with bromine atoms. In option C, the double bonds are replaced with an H atom and an OH group. In option D, there is no double bond and no electrophilic addition, since the reaction between aldehyde and HCN is nucleophilic addition. Thus option D is the correct answer.