Calculate ∆E° for the combustion of octane C8H18(l), to CO2 (g) and H2O (l). If the heat of combustion at constant pressure of octane is -5470.71 kJ/mol.

2C8H18 + 25O2(g) ==> 16CO2(g) + 18H2O(l)

dE = q + w
q = -5470.71 x 2 = ?
w = -pdV