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Science — CBSE Class 10 board question

Q1. [1]
The balanced chemical equation showing reaction between quicklime and water is :
  1. (a) 2 CaO + H₂O → 2 CaOH + H₂ + Heat
  2. (b) CaO + H₂O → Ca(OH)₂ + H₂ + Heat
  3. (c) CaO + H₂O → Ca(OH)₂ + Heat
  4. (d) 2 CaO + 3 H₂O → 2 Ca(OH)₃ + O₂ + Heat
Previously asked in CBSE board exam
2023 31/5/1 Q2
Generated by claude-sonnet-4-6 · 2026-06-14 10:29 · grounding rag
Model Answer

(c) CaO + H₂O → Ca(OH)₂ + Heat

Explanation

The textbook (Eq. 1.13) clearly states: CaO(s) + H₂O(l) → Ca(OH)₂(aq) + Heat. Only one mole each of CaO and H₂O react to form one mole of Ca(OH)₂ with no H₂ or O₂ released. Options (a), (b), and (d) are unbalanced or show incorrect products.

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