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

CBSE Class 10 Science 2026: question 27(b)

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

Q27(b) · 3 marks · Short answerAcids, Bases and Salts

Write the preparation of following compounds with balanced chemical equation:

  1. (i)

    Baking soda

    0 marks
  2. (ii)

    Bleaching powder

    0 marks
  3. (iii)

    Plaster of Paris

    0 marks

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

Baking soda uses brine, ammonia and CO₂.

Hint 2

Bleaching powder comes from chlorine and slaked lime. Plaster of Paris comes from heating gypsum.

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) Baking soda is made from sodium chloride, water, ammonia and carbon dioxide:

    1 mark
  2. (ii) Bleaching powder is made by passing chlorine over dry slaked lime:

    1 mark
  3. (iii) Plaster of Paris is made by heating gypsum at 373 K:

    1 mark

Answer: (i) NaCl + H₂O + CO₂ + NH₃ → NH₄Cl + NaHCO₃; (ii) Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O; (iii) CaSO₄·2H₂O → CaSO₄·½H₂O + 1½H₂O at 373 K

Where the marks are

  • Balanced equation for baking soda (1 mark)
  • Balanced equation for bleaching powder (1 mark)
  • Balanced equation for Plaster of Paris with 373 K (1 mark); ½ mark is deducted if any equation is not balanced

Revise the chapter

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.