One mole of methane undergoes complete combustion in a stoichiometric amount of air. The reaction proceeds as CH₄ + 2O₂ → CO₂ + 2H₂O. Both the reactants and products are in gas phase. ΔH°298 = - 730 kJ/mole of methane. Mole fraction of water vapour in the product gases is about

• A. 0.33
• B. 0.67
• C. 0.19
• D. 0.40

Answer: (C)