Q1. [1] § 1.1 CHEMICAL EQUATIONS § 1.2.1 Combination Reaction § 1.2.4 Double Displacement Reaction
C₆H₁₂O₆(aq) + 6O₂(g) → 6CO₂(g) + 6H₂O(l).
The above reaction is an example of
- (A) Displacement Reaction
- (B) Endothermic Reaction
- (C) Exothermic Reaction
- (D) Neutralisation Reaction
Previously asked in CBSE board exam
2026 31/4/1 Q18
Generated by claude-sonnet-4-6 · 2026-06-14 10:34 · grounding rag
Model Answer
(C) Exothermic Reaction
The given reaction is respiration, where glucose burns in oxygen releasing energy (heat). Reactions that release heat along with products are called exothermic reactions.
Source: Chapter 1, What you have learnt; Chapter 1, Exercise Q.10
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Explanation
- The key clue is that glucose reacts with oxygen to produce CO₂ and H₂O — this is cellular respiration, which releases energy, making it exothermic.
- Examiners expect you to recall that exothermic = heat released; endothermic = heat absorbed.
- It is not displacement (no element replacing another) or neutralisation (no acid-base), so eliminate those quickly.
- NCERT Exercise Q.10 directly asks why respiration is exothermic — link that knowledge here.
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