Question

what are the three stages that it takes for an equilibrium to become established?

Answer 1

I never heard of this. Obviously there be a beginning. A phase where the forward and reverse directions are adjusting themselves with respect to one another. When equilibrium is established you have the final stage. I have no idea if this is what you want or not but these what I have written sounds reasonable to me. Frankly, I see no reason for including the middle phase. You have the beginning and the end. It will its thing in the middle.