Water is added at a flow rate of 0.2 m3 /h in order to dilute the salt solution at a concentration of 1 mol/m3 and flow rate of 0.05 m3 /h in a well-mixed tank. The resulting solution leaves the tank at a flow rate of 0.15 m3 /h. Initially the tank contains 100 kg of fresh water and the flow rates remain constant throughout the process. (w=1000 kg/m3 ) Accordingly; a) Write the balance equations that describing the system dynamics b) Derive the expression for the variation of the output concentration and volume with time c) Calculate the output concentration in output stream and volume of solution inside the tank after 120 min. d) If the volume of the tank is 2 m3 , find the overflow time.