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The formula of functional… (Class 10 Science 2026, Q20)

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

CBSE Class 10 Science 2026: question 20

Set in the CBSE Class 10 board exam of 2026, paper 31/1/1, section B, question 20, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q20 · 1 mark · MCQCarbon and its Compounds

The formula of functional group for aldehyde is:

  1. (A)–COOH
  2. (B)–CHO
  3. (C)–C(=O)–
  4. (D)–OH

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

Hints

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

Hint 1

Aldehyde names end in '-al'.

Hint 2

In an aldehyde, the C=O carbon also carries a hydrogen atom.

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. Match each group to its class: –COOH is a carboxylic acid, –C(=O)– inside a chain is a ketone, and –OH is an alcohol.

  2. The aldehyde group is –CHO, for example methanal HCHO. Correct option: (B).

    1 mark

Answer: –CHO, option (B)

Where the marks are

  • Selects –CHO as the aldehyde group (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 31/1/1: 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.