Exercise 6.5: CSTR energy balance The liquid-phase reactions A B A C are each first order in the concentration of A. The feed to a nonisothermal CSTR con- tains pure A at 45 °C and 5 mol/L. Additional information for the reactions and the reactor are provided below. We want to operate this reactor such that the selectivity to B is greater than the selectivity to C, i.e., the rate at which B forms is greater than the rate at which C forms. Parameter Value Units Mt AHr1 93,200 -12,000 g/min cal/mol AHr2 -15,000 cal/mol 1000 L V 100 L/min Qf Cpf 0.22 cal/(g K) k1 k2 3.16 x 1014 exp(-12,500/T) 2.52 x 109 exp(-8,500/T) min -1; T in K min-1; T in K (a) Defining the selectivity as S = RB/Rc, determine the rate at which heat is trans- ferred to the surroundings to achieve a selectivity of five. (b) Determine the rate at which heat is transferred to the surroundings to achieve a selectivity of four. (c) Explain why the answer to Part A or Part B is greater.