MOLECULAR THERMODYNAMIC MODEL FOR EQUILIBRIA IN SOLUTION - I - REACTING AND NONREACTING ENSEMBLES

The partition functions of solution thermodynamics are mathematical re presentations of the properties of molecular ensembles statistically d istributed according to specific characteristics. The ensembles are cl assified as non-reacting or reacting. The non-reacting ensembles are c haracterized by one mean enthalpy level with dispersion around the mea n. The reacting ensembles are characterized by two or more distinctly separated enthalpy levels over which the different species are variabl y distributed, depending on concentration and/or temperature. The non- reacting ensembles can be distinguished into microcanonical, thermal, osmotic, thermo-osmotic ensembles, depending on the type of exchange w ith the surroundings which is connected to the fluctuations of the ens emble variables. The reacting ensembles can be distinguished into ther mal, osmotic, thermo-osmotic, electrochemical, electro-osmotic, electr othermal, electro-thermo-osmotic ensembles, depending on the type of r eaction and of exchange with the surroundings. (C) 1998 Elsevier Scien ce B.V.