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When 50g of lead powder… (Class 10 Science SQP 2024-25, Q5)

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ScienceCBSE Class 10 · Sample paper, session 2024-25 · 1 mark · MCQ

CBSE Class 10 Science sample paper 2024-25: question 5

From the official CBSE sample question paper for 2024-25, section A, question 5, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q5 · 1 mark · MCQMetals and Non-metals

When 50g of lead powder is added to 300 ml of blue copper sulphate solution, after a few hours, the solution becomes colourless. This is an example of

  1. (A)Combination reaction
  2. (B)Decomposition reaction
  3. (C)Displacement reaction
  4. (D)Double displacement reaction

Source: official sample paper from cbseacademic.nic.in (PDF). See it in the full Sample paper 2024-25.

Hints

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

Hint 1

Compare the reactivity of lead and copper.

Hint 2

Why would the blue colour of the solution disappear?

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. Lead is more reactive than copper, so it displaces copper from copper sulphate: .

    ½ mark

  2. The blue ions are removed, so the solution loses its colour. A more reactive metal replacing a less reactive one is a displacement reaction, option (C).

    ½ mark

Answer: Displacement reaction; option (C)

Where the marks are

  • States that Pb displaces Cu from CuSO₄ and chooses a displacement reaction (1 mark)

Revise the chapter

Practise this chapterBoard-style questions from Metals and Non-metals, one at a time, marked against the answer key and marking points.Back to the full paperSample paper 2024-25: 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.