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(i) Which method will be… (Class 10 Science 2026, Q27A)

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ScienceCBSE Class 10 · Board exam 2026, set 31/4/1 · 3 marks · Short answer

CBSE Class 10 Science 2026: question 27(A)

Set in the CBSE Class 10 board exam of 2026, paper 31/4/1, section B, question 27(A), for 3 marks. Try it first; the hints and our step-by-step solution are below.

Q27(A) · 3 marks · Short answerMetals and Non-metals

(i) Which method will be used to convert each of them to their respective metal oxides?
(a) Carbonate ore
(b) Sulphide ore
(ii) Write a chemical reaction to illustrate the use of aluminium for joining cracked railway tracks.
(iii) During extraction of metals, electrolytic refining is used to obtain pure metals. Which material will be used as anode and cathode for the refining of copper metal by this process?

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 31/4/1.

Hints

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

Hint 1

One method heats the ore in limited air, the other in excess air.

Hint 2

Aluminium is more reactive than iron. Which oxide can it reduce?

Hint 3

In refining, the metal to be purified dissolves away at one electrode and pure metal deposits at the other.

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. (i)(a) A carbonate ore is converted to the oxide by calcination, i.e. heating strongly in a limited supply of air. Example: .

    ½ mark

  2. (i)(b) A sulphide ore is converted to the oxide by roasting, i.e. heating strongly in excess air. Example: .

    ½ mark

  3. (ii) In the thermit reaction, aluminium reduces iron(III) oxide. The reaction is so exothermic that the iron formed is molten, and it is used to join cracked railway tracks:

    1 mark

  4. (iii) Anode: a thick rod or block of impure copper.

    ½ mark

  5. Cathode: a thin strip of pure copper. The electrolyte is acidified copper sulphate solution.

    ½ mark

Answer: (i) (a) Calcination, (b) Roasting. (ii) . (iii) Anode: impure copper; cathode: pure copper strip.

Where the marks are

  • States calcination for carbonate ore (½ mark)
  • States roasting for sulphide ore (½ mark)
  • Writes the balanced thermit reaction (1 mark)
  • Identifies the anode as impure copper (½ mark)
  • Identifies the cathode as pure copper (½ 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 paper2026 board paper, set 31/4/1: 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.