ENTHALPY CALCULATIONS

Calculate the enthalpy of formation (kJ/mol) of O2(g). The enthalpy of reaction for the equation as written is -1475.156 kJ/mol. If the answer is negative, enter the sign and then the magnitude.

2 C2H6(g) + 7 O2(g) → 2 CO2(g) + 3 H2O(l) .

ΔHof (kJ/mol)

C2H6(g)-84.667

O2(g)?

CO2(g)-393.5

H2O(l)-285.83