Enthalpy!!!?

Question

C3H6 + H2 -- C3H8 Change in H = -124KJ

C3H8 + 5 O2 -- 3 CO2 + 4 H20 Change in H= -2222Kj

H2 + 1/2 O2 -- H20 Change in H = -286KJ

Use to determine the standard enthalpy of combustion of propene::

C3H6 + 9/2 O2 --3 CO2 + 3 H20

Answer 1

The standard enthalpy are additive. So going from propene to CO2+H2O can be accomplished by going from propene to propane to CO2+ H2O PROVIDED THAT THE EQUATIONS ARE BALANCED. In this case, if we call the equations (1), (2), and (3) respectively, the process is (1) +(2) - (3). You can do the math.