Octane (C8H18) is a liquid hydrocarbon at room temperature that is the primary constituent of gasoline. (a)

Question:

Octane (C8H18) is a liquid hydrocarbon at room temperature that is the primary constituent of gasoline.
(a) Write a balanced equation for the combustion of C8H18(l) to form CO2(g) and H2O(l).
(b) Without using thermochemical data, predict whether ΔG° for this reaction is more negative or less negative than ΔH°.