The combustion of propane has the chemical equation: C3H8(g) 5 O2(g) -->3 CO2(g) 4 H2O(g). Why is this reaction NOT likely to be elementary

A5 mole sample of liquid acetone is converted to a gas at 75.0°c. if 628 j are required to raise the temperature of the liquid to the boiling point, 15.600 kj are required to evaporate the liquid, and 712 j are required to raise the final temperature to 75.0°c, what is the total energy required for the conversion?