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Which of the following… (Class 12 Chemistry 2023, Q1)

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ChemistryCBSE Class 12 · Board exam 2023, set 56/5/1 · 1 mark · MCQ

CBSE Class 12 Chemistry 2023: question 1

Set in the CBSE Class 12 board exam of 2023, paper 56/5/1, section A, question 1, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q1 · 1 mark · MCQHaloalkanes and Haloarenes

Which of the following molecules has a chiral centre correctly labelled with an asterisk (*) ?

  1. (A)
  2. (B)
  3. (C)
  4. (D)

Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 56/5/1.

Hints

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

Hint 1

A chiral carbon must be attached to four different groups.

Hint 2

For each starred carbon, list its four substituents and check whether any two are the same.

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. A chiral carbon carries four different groups. In (B) the starred carbon has , H, Cl and , which are all different, so it is chiral.

    1 mark

  2. In (A) and (C) the starred carbon carries two identical groups ( or ), and in (D) it carries two Br atoms, so none of these is chiral.

Answer: (B)

Where the marks are

  • Identifies option (B) as the molecule with a correctly labelled chiral centre (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Haloalkanes and Haloarenes, one at a time, marked against the answer key and marking points.Back to the full paper2023 board paper, set 56/5/1: 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.