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Saturday, 31 October

JEE Main 2020 · ChemistryMultiple choiceSingle correctHardMulti-step

JEE Main 3 September 2020, Shift 1, Chemistry Q41

Question 41 of 75 in this shift, Chemistry question 16 of 25.

Which of the following compounds produces an optically inactive compound on hydrogenation ?

The figure, in words

All four options are drawn structures (described in the option text); each drawn with H on a bold wedge and CH3 on a hashed bond at the central carbon.
  1. (1)[figure: drawn structure (skeletal line drawing) with a central carbon that has a bold wedge bond to H and a hashed bond to CH3; to the left a zigzag chain of three single bonds; to the right a single bond, then a double bond whose far end has two further single-bond line ends (one pointing up, one pointing down-right)]
  2. (2)[figure: drawn structure (skeletal line drawing) with a central carbon that has a bold wedge bond to H and a hashed bond to CH3; to the left a single bond to a vertex that has two line ends (one up-left, one down-left); to the right a single bond, then a double bond, then a single bond to a line end]
  3. (3)[figure: drawn structure (skeletal line drawing) with a central carbon that has a bold wedge bond to H and a hashed bond to CH3; to the left a single bond, then a double bond, then a single bond to a line end; to the right a single bond down-right and then a single bond up-right to a line end]
  4. (4)[figure: drawn structure (skeletal line drawing) with a central carbon that has a bold wedge bond to H and a hashed bond to CH3; to the left a single bond to a vertex that has two line ends (one up-left, one down-left); to the right a single bond to a vertex that has a double bond to a line end (up-right) and a single bond to a line end (down-right)]Official answer

Official answer

Option 4

NTA final key (Sep 2020).

Chapter
Hydrocarbons
Topic
Stereoisomerism
Idea tested
Chiral Centers

Same idea in other shifts

Asked 12× in all
  1. 4 Apr 2026, Shift 2 · Q65The following structures are [figure: stereocentre C with Br (up), CH3 (hashed, left), Me (down), Cl (wedge, right)] and [figure:…EasyDiagram basedHas a figure
  2. 8 Apr 2024, Shift 2 · Q89Total number of optically active compounds from the following is ___________. (1) Fischer projection: CH3\mathrm{CH_3} on top; H-C-OH;…MediumNumerical valueHas a figure
  3. 1 Feb 2024, Shift 1 · Q89Number of optical isomers possible for 2-chlorobutane ________.EasyNumerical value
  4. 11 Apr 2023, Shift 2 · Q79Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : A solution of the…MediumAssertion–reason
  5. 29 Jul 2022, Shift 2 · Q75Given below are two statements. Statement I: The compound [figure: compound (A), a drawn structure with a stereocentre bearing…MediumTwo statementsHas a figure
  6. 29 Jun 2022, Shift 1 · Q89Observe structures of the following compounds [figure: five structures] The total number of structures/compounds which possess asymmetric…EasyNumerical valueHas a figure
  7. 29 Jun 2022, Shift 2 · Q88The number of chiral alcohol(s) with molecular formula C4H10O\mathrm{C_4H_{10}O} is _____.MediumNumerical value
  8. 8 Jan 2020, Shift 1 · Q50The number of chiral centres in penicillin is ______.MediumNumerical value

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 108 of the 174 JEE Main shifts held from 2017 to 2026.