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Saturday, 31 October

JEE Main 2020 · ChemistryMultiple choiceSingle correctMediumConceptual

JEE Main 9 January 2020, Shift 2, Chemistry Q40

Question 40 of 75 in this shift, Chemistry question 15 of 25, Section A.

Which of the following has the shortest C-Cl bond ?
  1. (1)Cl−CH=CH2\mathrm{Cl-CH=CH_2}
  2. (2)Cl−CH=CH−NO2\mathrm{Cl-CH=CH-NO_2}Official answer
  3. (3)Cl−CH=CH−CH3\mathrm{Cl-CH=CH-CH_3}
  4. (4)Cl−CH=CH−OCH3\mathrm{Cl-CH=CH-OCH_3}

Official answer

Option 2

NTA final key (Jan 2020).

Idea tested
Mesomeric Effect

Same idea in other shifts

Asked 9× in all
  1. 2 Apr 2026, Shift 2 · Q63Given below are two statements: Statement I: In…MediumSingle correct
  2. 6 Apr 2026, Shift 2 · Q63Shown below is the structure of methyl acetate with three different α\alpha, β\beta and γ\gamma carbon - oxygen bonds. The correct…MediumDiagram basedHas a figure
  3. 4 Apr 2024, Shift 1 · Q74Match List I with List II : List - I (Mechanism steps) List - II (Effect) (A) [structure: aniline, lone pair on NH2_2 donated into ring,…MediumMatch the listHas a figure
  4. 9 Apr 2024, Shift 1 · Q89How many compounds among the following compounds show inductive, mesomeric as well as hyperconjugation effects ? [figure: eight…MediumNumerical valueHas a figure
  5. 1 Feb 2024, Shift 2 · Q73The functional group that shows negative resonance effect is :EasySingle correct
  6. 29 Jan 2024, Shift 1 · Q72The interaction between π\pi bond and lone pair of electrons present on an adjacent atom is responsible forEasySingle correct
  7. 8 Jan 2020, Shift 1 · Q41Arrange the following compounds in increasing order of C−-OH bond length : methanol, phenol, p-ethoxyphenolMediumSingle correct
  8. 4 Sep 2020, Shift 2 · Q39Among the following compounds, which one has the shortest C−-Cl bond ?MediumDiagram basedHas 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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.