Skip to content

What is IUPAC name of… (Class 12 Chemistry SQP 2023-24, Q4)

questionbuddy.in/q/cbse-12-chemistry-2023-24-sqp-q4-iupac-name-ketone-undergoes-iodoform

ChemistryCBSE Class 12 · Sample paper, session 2023-24 · 1 mark · MCQ

CBSE Class 12 Chemistry sample paper 2023-24: question 4

From the official CBSE sample question paper for 2023-24, section A, question 4, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q4 · 1 mark · MCQAldehydes, Ketones and Carboxylic Acids

What is IUPAC name of the ketone A, which undergoes iodoform reaction to give and yellow precipitate of ?

  1. (A)3-Methylpent-3-en-2one
  2. (B)3-Methylbut-2-en- one
  3. (C)2, 3-Dimethylethanone
  4. (D)3-Methylpent-4-one

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2023-24.

Hints

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

Hint 1

The iodoform reaction converts –COCH₃ into –COONa.

Hint 2

Add back the CH₃ group and number the chain so the C=O carbon gets the lowest locant.

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. In the iodoform reaction, , so R = .

  2. The ketone is , named 3-methylpent-3-en-2-one.

    1 mark

Answer: (A) 3-Methylpent-3-en-2-one

Where the marks are

  • Reconstructs the methyl ketone and names it correctly (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Aldehydes, Ketones and Carboxylic Acids, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2023-24: 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.