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Enthalpy of CH₄ + 2O₂ → CH₃OH is negative. If enthalpy of combustion of CH₄ and CH₃OH are x and y respectively, then which relation is correct
- x > y
- x < y
- x = y
- x ≥ y
Correct answer: x < y
Solution
The enthalpy of combustion of CH₄ is the negative of its heat of formation, and the enthalpy of combustion of CH₃OH is the negative of its heat of formation. Since the heat of formation of CH₃OH is greater than that of CH₄, the enthalpy of combustion of CH₄ is less than that of CH₃OH.
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