1.A lake with constant volume 10X10^6 m^3 is fed by a pollution-free stream with flow rate 50 m^3/s. A factory dumps 5m^3/s of a neoconservative waste with concentration 100 mg/L into the lake. The pollution has a reaction rate coefficient K of 0.25/day. Assuming the pollution is well mixed in the lake, find the steady-state concentration of pollution in the lake.
2.We have a situation where hydrogen gas at 300 degrees C is flowing out of a tube at the rate of 100 mL/min. The tube is located in a fume hood operating at 25 degrees C and 1 atm. What is the flow rate of air that must be entering the hood so that the hydrogen gas does not pose a flammability hazard?