Ahot toluene stream, which has mass flow rate of 8.0 kg/min, is cooled by cooling water in a cocurrent heat exchanger; its temperature drops from 90o c to 60o c after passing through the heat exchanger. the cooling water stream has a mass flow rate of 10 kg/min and an inlet temperature of 20o c. given that the specific heats of toluene and water are 0.41 and 1.00 kcal/(kg. o c), respectively, determine (a, 3%) the heat duty of the heat exchanger, (b,3%) the temperature of the cooling water leaving the heat exchanger, (c, 3%) the log mean temperature difference (or "driving force") for the heat exchange process, and (d, 3%) the ua value of the heat exchanger. assume a negligible heat loss to the surroundings.