Consider the following system of gas-phase reactions: B is the desired product, and X and Y are foul pollutants that are expensive to get rid of. The specific reaction rates are at 27 C. The reaction system is to be operated at 27 C and 4 atm. Pure A enters the system at a volumetric flow rate of 10 dm 3 /min. (a) Sketch the instantaneous selectivities as a function of the concentration of C A . (b) Consider a series of reactors. What should be the volume of the first reactor