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Design an experimental… (Class 10 Science 2025, Q28b)

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ScienceCBSE Class 10 · Board exam 2025, set 31/3/1 · 3 marks · Short answer

CBSE Class 10 Science 2025: question 28(b)

Set in the CBSE Class 10 board exam of 2025, paper 31/3/1, section C, question 28(b), for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q28(b) · 3 marks · Short answerAcids, Bases and Salts

Design an experimental set-up to demonstrate that "Alcohol and glucose contain hydrogen but are not categorised as acids". Also give the reason to justify this fact.

Source: official question paper from cbse.gov.in (PDF). See it in the full 2025 board paper, set 31/3/1.

Hints

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

Hint 1

Use a circuit with a bulb to test whether a solution conducts.

Hint 2

Conduction needs ions – which ion do acids produce?

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. Set-up: fix two iron nails on a rubber cork in a 100 mL beaker; connect them through a bulb, a switch and a 6 V battery. Pour dilute HCl into the beaker and switch on – the bulb glows. Repeat with dilute – the bulb glows.

    1 mark

  2. Now repeat separately with glucose solution and alcohol solution – the bulb does not glow, so these solutions do not conduct electricity.

    1 mark

  3. Reason: acids dissociate in water to give ions which carry current; glucose and alcohol contain hydrogen but do not release ions in water, so they are not acids.

    1 mark

Answer: Bulb glows with acid solutions but not with glucose/alcohol solutions, since only acids release ions in water.

Where the marks are

  • Correct circuit set-up with acid solutions – bulb glows (1 mark)
  • Glucose/alcohol – bulb does not glow (1 mark)
  • Reason: no ions produced by glucose/alcohol (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Acids, Bases and Salts, one at a time, marked against the answer key and marking points.Back to the full paper2025 board paper, set 31/3/1: 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.