for a particular isomer C8H18, the following reaction produces 5113.3 kj of heat per mole of C8H18 consumed under standard conditions

c8h18(g) + 25/2 O2 (g) ---> 8co2(g) + 9h2o(g)

what is the standard enthalpy of formation of this isomer of c8h18?

o2= 0
co2(g)= -393.5
h2o(g)= -241.8

2 answers

delta h= -5113.3
Are all those kJ/mol?
is that -5112.3 kJ/mol for delta H rxn (combustion)?
-5113.3 = [(8*-393.5) +(9*-241.8)]-[dHf C8H18]