Bifurcation Sequence.

In the systems far from equilibrium the procedure of a chemical reaction between the components does not always correspond to the macroscopic equations. The elementary act of collision of the components and the nature of the reaction products being formed depend on the energy of the colliding molecules, on their correct spatial orientation. Collision of the initial components and formation of the reaction products are proportional to the motive force of the process which is normally perceived as affinity. According to de Donder, affinity is determined by the relationship of chemical potentials of substances undergoing a chemical reaction. 

If several reactions proceed in the system, affinity and transformations of the components must be determined separately for each reaction. In the chemical reaction at the bifurcation point, the system loses stability, and passes to a nonequilibrium state, which makes it possible to assume a new quality of evolution of the dynamic system. There takes place a change in the nature of motion and structure of the system. When the system moves to the bifurcation point, an important role is played by the chemical potential and affinity of the system.(Read more)