Question

 When 2 moles of C₂H₆ (g) are completely burnt 3120 kJ of heat is liberated. Calculate the enthalpy of formation, of C₂H₆ (g). Given ∆_fH for CO₂ (g) and H₂O (l) are – 395 &286 kJ respectively.

Answer 1

2C₂ H₆ + 7O₂ → 4CO₂ + 6H₂O

∆H_comb = ∆H for reactants – ∆H_f products