Since alkyl group has +I-effect and aryl group has +R-effect, thus greater the number of alkyl and aryl groups attached to the carbonyl group, its reactivity towards nucleophilic addition reaction. Secondly, as the steric crowding on carbonyl group increases, the reactivity decreases accordingly. ∴ Correct reactivity order for reaction with PhMgBr is 
The order of reactivity of phenyl magnesium bromide (PhMgBr) with the following compounds NEET 2011 Chemistry, Aldehydes and Ketones — question figure
NEET UG 2011 — Chemistry Organic Chemistry
2011mcqmedium
The order of reactivity of phenyl magnesium bromide (PhMgBr) with the following compounds 
Official previous-year question
Held on 30 Apr 2011 · Verified 9 Jul 2026.
Options
- A
III > II > I
- B
II > I > III
- C
I > III > II
- D
I > II > III
Did you get this right?
Sign in to track your attempts and accuracy.
Your note
Sign in to keep a private note on this question. Nothing you write is ever public.
NEET UG Organic Chemistry in other years
More NEET UG Organic Chemistry questions
Which of the following is a reducing sugar?
2026easy
Markovnikov's rule is applicable to:
2026easy
Name the class of enzyme that usually catalyze the following reaction : $\mathrm{S}-\mathrm{G}+\mathrm{S}^{\#} \rightarrow \mathrm{~S}+\mathrm{S}^{\#}-\mathrm{G}$ Where, $G \rightarrow$ a group other than hydrogen $S \rightarrow$ a substrate $\mathrm{S}^{\#} \rightarrow$ another substrate
2025medium
Identify the suitable reagent for the following conversion 
2025medium
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : undergoes $\mathrm{S}_{\mathrm{N}} 2$ reaction faster than Reason (R) : Iodine is a better leaving group because of its large size. In the light of the above statements, choose the correct answer from the options given below :
2025easy
Other Chemistry topics for NEET UG
Keep practicing Organic Chemistry
Work through every NEET UG Organic Chemistry PYQ, year by year.