How do I calculate enthalpy of combustion?

Calculate the enthalpy of combustion, Delta H comb, for C6H14...?

• You'll first need to determine the balanced chemical equation for the combustion of C6H14. (Express your answer to four significant figures and include the appropriate units.) /\ H comb = __________ --------------------------------------... Don't know if this info is necessary for this question, but here it is.. [[[[[ Enthalpies of formation ]]]] Substance ________ C6H14(l)___O2(g)___CO2(g)___H2O(l) /\ H f (kJ / mol) ______ -204.6 _____ 0 _____-393.5 ___-285.8

• Answer:

  http://answers.yahoo.com/question/index?qid=20100304072518AAlS8ys delta H = [ 6 X -393.5 + 7 X -285.8 ] - [ -204.6 + 19/2 X 0 ] delta H = [ -2361 - 2000.6 ] + 204.6 delta H = -4361.6 + 204.6 = -4157 kj/mole