A 90-wt-% aqueous H2SO4 solution at 25C is added over a period of 6 hours to a tank containing 4000 kg of pure water also at 25C. The final concentration of acid in the tank is 50- wt-%. The contents of the tank are cooled continuously to maintain a constant temperature of 25C. Because the cooling system is designed for a constant rate of heat transfer, this requires the addition of acid at a variable rate. Determine the instantaneous 90-%-acid rate as a function of time, and plot this rate (kg-s-1) vs. time. The data of the preceding problem may be fit to a cubic equation expressing HF/(X9X2) as a function of X1, and the equations of the preceding problem then provide expressions for f and hE. A 90-wt-% aqueous H2SO4 solution at 25C is added over a period of 6 hours to a tank containing 4000 kg of pure water also at 25C. The final concentration of acid in the tank is 50- wt-%. The contents of the tank are cooled continuously to maintain a constant temperature of 25C. Because the cooling system is designed for a constant rate of heat transfer, this requires the addition of acid at a variable rate. Determine the instantaneous 90-%-acid rate as a function of time, and plot this rate (kg-s-1) vs. time. The data of the preceding problem may be fit to a cubic equation expressing HF/(X9X2) as a function of X1, and the equations of the preceding problem then provide expressions for f and hE