A reaction-diffusion equation describes how chemical concentration changes due to two factors simultaneously, reaction and movement. A simple model has the form

The first term describes diffusion, and the second term R(C) is the reaction, which could have a positive or negative sign (depending on whether chemical is being created or destroyed). Suppose that β = 1.0/min, and Г = 5.0 mol/L. For each of the following forms of R(C),
a. Describe how the reaction rate depends on the concentration.
b. Find the equilibria and their stability.
c. Describe how absorption changes the results.
Suppose that R(C) = -C.

dc -Mr-c) + R(C). dt