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An iron nail is added… (Class 10 Science SQP 2025-26, Q19)

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ScienceCBSE Class 10 · Sample paper, session 2025-26 · 1 mark · MCQ

CBSE Class 10 Science sample paper 2025-26: question 19

From the official CBSE sample question paper for 2025-26, section B, question 19, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q19 · 1 mark · MCQChemical Reactions and Equations

An iron nail is added to each of the two test tubes 'P' and 'Q' containing aqueous copper (II) sulphate, and aqueous silver nitrate respectively. Which of the following observation is correct?

  1. (A)In test tube 'P' iron nail is coated with a blue coating and in test tube 'Q' there is no reaction.
  2. (B)Iron nail is coated with a brown coating in test tube 'P' and silver coating in test tube 'Q'.
  3. (C)There is no reaction in either of the test tubes 'P' or 'Q'.
  4. (D)There is no reaction in test tube 'P' but a silver coating on iron nail is seen in test tube 'Q'.

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2025-26.

Hints

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

Hint 1

Compare the positions of Fe, Cu and Ag in the reactivity series.

Hint 2

What colour is a copper deposit, and what colour is a silver deposit?

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. Iron is more reactive than both copper and silver, so it displaces them from their salt solutions.

  2. In P: Fe + CuSO → FeSO + Cu, which deposits a reddish-brown coating of copper on the nail. In Q: Fe + 2AgNO → Fe(NO) + 2Ag, which deposits a silvery coating. Answer: option (B).

    1 mark

Answer: Option (B): brown coating in P, silver coating in Q

Where the marks are

  • Uses the reactivity series (Fe above Cu and Ag) to predict copper and silver deposits, option (B) (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Chemical Reactions and Equations, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2025-26: 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.