Consider a mixture distribution formed by taking a weighted sum of three normal distributions and given by

.

You can change this distribution's properties by varying , , , and . This Demonstration plots this distribution. For specific values of , , , and , you can obtain a bimodal distribution, which mimics the residence time distribution (or ) of a batch reactor.

The following sequential reaction mechanism takes place in this reactor:

All rate constants are set equal to one. Initially, the reactor contains only species and .

The segregation model and the function allow the calculation of the exit concentration as a function of time for all species. This Demonstration gives the exit concentration in light blue, magenta, brown, green, and dark blue for species , , , , and , respectively. The first two snapshots show: (1) a bimodal and (2) the batch reactor's exit concentrations versus time, which present two plateaus as expected.