Probability and thermodynamic space in a statistical model for potentiometry, calorimetry, and thermal analysis

The use of statistical thermodn. anal. is demonstrated by showing how the exptl. detns. of thermodn. parameters by potentiometry, isothermal and adiabatic calorimetry, and differential scanning calorimetry can be explained. The use of the partition function method to describe equil. in soln. is founded on the assumption of a quantized energy level modes. Each level corresponds in protonation equil. to one protonation species. The partition function can be factorized into enthalpy and entropy contributions, and thus is representative of the grand canonical ensemble. The probability space can be transformed into the thermodn. space by taking the log of the equation and the relations between the thermodn. functions are represented by vectors. The relation between chem. energy and thermal energy in thermodn. space is examd.; chem. energy measured by enthalpy changes corresponds to a decrease of kinetic energy of the stable complexes with respect to the less stable ones. If no reaction takes place, the only change that can be measured is thermal energy; the model of this system is a canonical ensemble exchanging heat but not matter with surroundings.