[Big-Daddy]

Let's say I have a general phase transition S (phase 1)  S (phase 2). At a certain point in pressure and temperature for each phase (they can have different pressures and temperatures, we might say P₁ and T₁ for phase 1 and P₂ and T₂ for phase 2), how might we express the forward and reverse rates of this phase transition?

No doubt the forward rate will be a function of P₁, T₁ and the activity of S (phase 1); the backward rate will presumably be an analogous function of P₂, T₂ and the activity of S (phase 2). But what function? And how should we work out how much the temperature of phase 1 changes on the basis of how many moles/what activity of S (phase 1) there is, and temperature of phase 2 changes on the basis of how many moles/what activity of S (phase 2) there is.