Reaction in an Isothermal CSTR
In this Demonstration, the liquidphase reaction A → B takes place in an isothermal, continuous stirredtank reactor (CSTR). Use the sliders to set the feed concentration of A, C_{A,0}, the volumetric flow rate and the rate constant k. Select the reaction order with respect to A using the "1^{st}" or "2^{nd}" button. The rate constant has the same numerical value when the reaction order changes, but its units are different. The figure shows the feed molar flow rate F_{A,0}], the feed concentration C_{A,0}, the outlet molar flow rates F_{A}, F_{B} and the outlet concentrations C_{A}, C_{B}. Note that the outlet concentrations are identical to the concentrations in the reactor. The reactor residence time τ=V/v is also calculated. Download the CDF file to view the simulation using the free Wolfram CDF player. 

Details
The constantdensity, liquidphase reaction takes place in an isothermal CSTR: A → B, with reaction rate r_{A} = r_{B} = kC_{A}^{m }where C_{A} is the concentration of component A, r_{i} is the rate of reaction of component i, m is the order of reaction with respect to A and k is the rate constant.
Mass balances on each component:
Mass balances in terms of volumetric flow rates and concentration:
The solution to these mass balances for first and secondorder reactions are:
The constantdensity, liquidphase reaction takes place in an isothermal CSTR: A → B, with reaction rate r_{A} = r_{B} = kC_{A}^{m }where C_{A} is the concentration of component A, r_{i} is the rate of reaction of component i, m is the order of reaction with respect to A and k is the rate constant.
Mass balances on each component:
component A: F_{A,0}  F_{A} + r_{A}V = 0
component B: F_{B,O}  F_{B} + r_{B}V = 0
Mass balances in terms of volumetric flow rates and concentration:
component A: C_{A,0}v  C_{A}v + r_{A}V = 0F_{i,0} is the molar flow rate of component i at the inlet, F_{i} is the molar flow rate of component i at the outlet. C_{i,0} and C_{i} are molar concentrations of component i at the inlet and outlet, respectively; and v is the volumetric flow rate, which is equal at the inlet and outlet for constantdensity reactions.
component B: C_{B,0}v  C_{B}v + r_{B}V= 0
The solution to these mass balances for first and secondorder reactions are:
first order:
C_{A}(τ) = C_{A,0}  C_{A,0}e^{kτ}C_{B}(τ) = C_{B,0} + (C_{A,0}  C_{A,0}e^{kτ})
second order: C_{A}(τ) = C_{A,0}  [(1/C_{A,0}) + kτ]^{1}where τ = V/v is the residence time in the reactor.