Hexane is a saturated hydrocarbon that exists in liquid form. It burns in air to give CO2 and water

C6H6 (l) + 15/2 O2 → 6 CO2 + 3H2O (l)

The activation energy for the forward reaction is

a) –25 kJ
b) 25 kJ
c) 40 kJ
d) –65 kJ
e) –80 kJ

The activation energy for the forward reaction cannot be determined from the given information.