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Which of the following set of… (Class 10 Science 2026, Q18)

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ScienceCBSE Class 10 · Board exam 2026, set 31/5/1 · 1 mark · MCQ

CBSE Class 10 Science 2026: question 18

Set in the CBSE Class 10 board exam of 2026, paper 31/5/1, section B, question 18, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q18 · 1 mark · MCQCarbon and its Compounds

Which of the following set of compounds does not belong to same homologous series ?

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

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 31/5/1.

Hints

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

Hint 1

Check each formula against the general formula .

Hint 2

Find the formula that has fewer hydrogens than this rule predicts.

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. fits , so it is an alkene. fits , so it is an alkane.

  2. Every other pair contains only alkanes. So (D) is the pair that is not from the same homologous series.

    1 mark

Answer: (D)

Where the marks are

  • Recognises alkene vs alkane (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Carbon and its Compounds, one at a time, marked against the answer key and marking points.Back to the full paper2026 board paper, set 31/5/1: 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.