The standard enthalpy of combustion of C2H6O(l) is -1,367 kJ mol-1 at 298 K. What is the standard enthalpy of formation of C2H6O(l) at 298 K? Give your answer in kJ mol-1, rounded to the nearest kilojoule. Do not include units as part of your answer.

Question

Note: The standard enthalpies of formation of CO2(g) and H2O(l) are -394 and -286 kJ mol-1, respectively, at 298 K.

Answer 1

C2H6O + 3O2 ==> 2CO2 + 3H2O
dHrxn = (n*dHfproducts) - (n*dHfreactants)
Substitute and solve for dHfC2H6O