Answer to Question #59760 in General Chemistry for tom

Question

Calculate the enthalpy change of the reaction below by two different methods.
C3H8(g) + 5O2(g) ------> 3CO2(g) + 4H2O(g)

a) Use the standard enthalpies of formation:
C3H8(g)- 104kJ mol -1
CO2(g)- 394 kJ mol-1
H2O(g)- 242kJ mol-1

b) Use the following mean bond enthalpies quoted in kJmol-1.
C-C 348, C-H 412, O=O 496, C=O 804 and O-H 463

c)Account for any difference between the two values.