Using the following equation for the combustion of octane, calculate the heat of reaction for 50.00 g of octane. the molar mass of octane is 114.33 g/mole. 2 c8h18 + 25 o2 -> 16 co2 + 18 h2o hrxn = -11018 kj using the following equation for the combustion of octane, calculate the heat of reaction for 50.00 of octane. the molar mass of octane is 114.33 . 2 + 25 16 + 18 = -11018 -2.410 kj -6300 kj -4820 kj -2410 kj