8. For the following conditions, determine whether a CSTR or a PFR is more efficient in removing a reactive compound from the waste stream under steady-state conditions with a first-order reaction: Two reactors' volume, flow rate, and reaction rate constant are the same: reactor volume =280m3, flow rate =14m3/d, and first-order reaction rate constant =0.05d1.(15pts) 9. A person weighing 60.0kg requires approximately 1,500kcal for simple existence, such as eating and sitting in a chair. Approximately 60% of all the energy in the foods we eat becomes heat. Still, more energy becomes heat as it is transferred to functional systems of the cells. The functioning of the cells releases still more energy so that ultimately "all the energy released by metabolic processes eventually becomes heat." Some of this heat is used to maintain the body at a normal temperature of 37C. What fraction of the 1,500kcal is used to maintain the body temperature at 37C if the room temperature is 25C ? Assume the specific heat of a human is 3.5kJ/kgK.(10 pts)