Positional microstates and probability fields in real systems

Abstract A previously published paper provided six examples of spontaneous processes for ideal systems that cannot be explained using classical thermodynamics. These six examples include free expansion of an ideal gas, mixing of ideal gases, diffusion of an ideal solute, mixing of ideal solutes, osmosis with ideal solutions, and free discharge of a concentration battery with ideal solutions. The previous paper demonstrated how energy was not a driving force in any of these examples and then proceeded to develop a positional entropy model, S D , that explains why these spontaneous processes occur. This new paper provides a method for calculating positional entropy, S D , for the same six systems, but for real particles that include nonzero volumes, particles with different volumes, and particles with different particle-particle interactions. The important outcome of this work shows that spontaneous discharge of these six example systems, either for ideal or real particles, is the result of a probability field created by the non-equilibrium distribution of the microstates that exists after the constraints on the system are changed, e.g., by removal of a separating partition or the shorting of a concentration cell. The probability field biases the movement of the particles toward the equilibrium distribution, where the bias is a consequence of an increased probability and not because of a decrease in energy. An additional conclusion of this work shows that the discharge of the probability field to the final equilibrium distribution of positional microstates removes the potential energy in the system but does not violate the law of conservation of energy.