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Science — CBSE Class 10 board question

Q1. [1]
The correct balanced chemical equation showing exothermic reaction in which natural gas burns in air is :
  1. (A) CH₄ + O₂ ⎯⎯→ CO₂ + 2H₂O
  2. (B) CH₄ + 2O₂ ⎯⎯→ 2CO₂ + 2H₂O + Energy
  3. (C) CH₄ + 2O₂ ⎯⎯→ CO₂ + 2H₂O
  4. (D) CH₄ + 2O₂ ⎯⎯→ CO₂ + 2H₂O + Energy
Previously asked in CBSE board exam
2025 31/2/1 Q1
Generated by claude-sonnet-4-6 · 2026-06-14 10:31 · grounding rag
Model Answer

(D) CH₄ + 2O₂ ⎯⎯→ CO₂ + 2H₂O + Energy

Explanation

The equation must be balanced (2O₂ on LHS; 1C, 4H, 4O on each side) and show energy released (exothermic). Option A is unbalanced; B has wrong products (2CO₂); C is balanced but missing energy. Only D is both correctly balanced and shows energy as a product of this exothermic combustion reaction.

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