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Friday, 9 October

JEE Main 2021 · ChemistryMultiple choiceSingle correctMediumConceptual

JEE Main 3 August 2021, Shift 2, Chemistry Q43

Question 43 of 90 in this shift, Chemistry question 13 of 30, Section A.

Order of reactivity for hydrolysis of substituted chlorobenzenes in the presence of aqueous NaOH is

The figure, in words

Four substituted chlorobenzenes: (A) chlorobenzene; (B) 4-nitrochlorobenzene (NO2 para to Cl); (C) 2,4-dinitrochlorobenzene (NO2 ortho and para to Cl); (D) 2,4,6-trinitrochlorobenzene (NO2 at both ortho and para positions).
  1. (1)C>B>D>AC > B > D > A.
  2. (2)A>B>C>DA > B > C > D
  3. (3)D>C>B>AD > C > B > AOfficial answer
  4. (4)B>C>D>AB > C > D > A

Official answer

Option 3

NTA final key.

Chapter
Haloalkanes and Haloarenes
Topic
Aromatic Hydrocarbons
Idea tested
SNAr and Meisenheimer Complex

Same idea in other shifts

Asked 3× in all
  1. 31 Jan 2024, Shift 2 · Q76Identify A and B in the following reaction sequence. [reaction: bromobenzene --(Conc HNO3_3)--> A --((i) NaOH, (ii) HCl)--> B]HardDiagram basedHas a figure
  2. 8 Apr 2023, Shift 2 · Q73The correct order of reactivity of following haloarenes towards nucleophilic substitution with aqueous NaOH is : A. [chlorobenzene] B.…MediumSingle correctHas a figure

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.