AP Chemistryhardmcq1 pt
Calculate ΔH° for CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(l). (ΔH°_f: CH₄ −74.8, CO₂ −393.5, H₂O(l) −285.8 kJ/mol)
A.−890.3 kJ
B.−604.7 kJ
C.+890.3 kJ
D.−965.1 kJ
Explanation
Core Concept
Products: −393.5 + 2(−285.8) = −965.1. Reactants: −74.8 + 0. ΔH° = −965.1 − (−74.8) = −890.3 kJ — methane's combustion enthalpy.
Correct Answer
A−890.3 kJ
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