When octane burns in an automobile engine, heat is released to the air and to the metal in the car engine, but a significant portion is absorbed by the liquid in the cooling system - an aqueous solution of ethylene glycol. What mass of octane is completely burned to cause the heating of 20 kg of aqueous ethylene glycol automobile coolant from 10 C to 70 C? The specific heat capacity of the aqueous ethylene glycol is 3.5 J/gC. Assume water is produced as a gas and that all the heat flows into the coolant.