Use the information provided to calculate the standard enthalpy of formation of acetylene, C₂H₂(g), in kJ·mol–1.
C₂H₂(g) + 5/2O₂(g) → 2CO₂(g) + H₂O(l) ∆H˚ = –1299.5 kJ
C(s) + O₂(g) → CO₂(g) ∆H˚ = –393.5 kJ
H₂(g) + 1/2O₂(g) → H₂O(l) ∆H˚ = –285.8 kJ

Question

Use the information provided to calculate the standard  enthalpy of formation of acetylene, C2H2(g), in kJ·mol–1.
C2H2(g) + 5/2O2(g) →  2CO2(g) + H2O(l) ∆H˚ = –1299.5 kJ
C(s) + O2(g) → CO2(g) ∆H˚ = –393.5 kJ
H2(g)  + 1/2O2(g) → H2O(l) ∆H˚ = –285.8 kJ

Accepted Answer

Correct answer: C.

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