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Consider the reaction… (Class 12 Chemistry SQP 2025-26, Q2)

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ChemistryCBSE Class 12 · Sample paper, session 2025-26 · 1 mark · MCQ

CBSE Class 12 Chemistry sample paper 2025-26: question 2

From the official CBSE sample question paper for 2025-26, section A, question 2, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q2 · 1 mark · MCQAlcohols, Phenols and Ethers

Consider the reaction and identify B and C

and

  1. (A)B=C= Butanol
  2. (B)B= Butanol, C=Butene
  3. (C)B= Butan-2-ol, C= Butanol
  4. (D)B= Butene, C=Butan-2-ol

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2025-26.

Hints

Open one hint at a time and try again before the next.

Hint 1

Alcoholic NaOH gives an alkene.

Hint 2

Compare Markovnikov hydration with hydroboration–oxidation.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

  1. Alcoholic NaOH causes dehydrohalogenation: A = but-1-ene, .

  2. Acid-catalysed hydration follows Markovnikov's rule: B = butan-2-ol. Hydroboration–oxidation gives the anti-Markovnikov product: C = butan-1-ol.

    1 mark

Answer: B = Butan-2-ol, C = Butanol; option (C)

Where the marks are

  • Correct identification of B (Markovnikov) and C (anti-Markovnikov) (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Alcohols, Phenols and Ethers, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2025-26: every question, by section.

The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.