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Friday, 9 October

JEE Main 2024 · ChemistryMultiple choiceDiagram basedMediumMulti-step

JEE Main 29 January 2024, Shift 1, Chemistry Q76

Question 76 of 90 in this shift, Chemistry question 16 of 30, Section A.

The final product A formed in the following multistep reaction sequence is

The figure, in words

Reaction scheme: styrene (benzene ring bearing a vinyl group) with reagents (i) H2O, H+ (ii) CrO3 (iii) H2N-NH2, KOH, heating, giving product A.
  1. (1)[figure: ethylbenzene, C6H5CH2CH3\mathrm{C_6H_5CH_2CH_3}]Official answer
  2. (2)[figure: hydrazone of phenylacetaldehyde, C6H5CH2CH=N−NH2\mathrm{C_6H_5CH_2CH=N-NH_2}]
  3. (3)[figure: hydrazone of acetophenone, C6H5C(CH3)=N−NH2\mathrm{C_6H_5C(CH_3)=N-NH_2}]
  4. (4)[figure: phenylacetic acid, C6H5CH2COOH\mathrm{C_6H_5CH_2COOH}]

Official answer

Option 1

NTA final key.

Chapter
Aldehydes, Ketones and Carboxylic Acids
Topic
Alkanes and Free Radicals
Idea tested
Wolff-Kishner Reduction to Alkanes

Same topic in other shifts

All Alkanes and Free Radicals questions
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  3. 5 Apr 2026, Shift 2 · Q72RMgI when treated with ice cold water liberated a gas which occupied 1.4 dm3^3/g at STP. The gas produced is further reacted with iodine…MediumNumerical value
  4. 6 Apr 2026, Shift 1 · Q65Given below are two statements: Statement I: Methane can be prepared by decarboxylation of sodium ethanoate, Kolbe's electrolysis of…MediumTwo statements
  5. 6 Apr 2026, Shift 2 · Q72An alkane (Y) requires 8 moles of oxygen for complete combustion and on chlorination with Cl2/hν\mathrm{Cl_2}/h\nu, (Y) gives only one…MediumNumerical value
  6. 8 Apr 2026, Shift 2 · Q65n-Butane on monochlorination under photochemical condition gives an optically active compound "P". "P" on further chlorination gives…MediumSingle correct

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.