NEW CHEMICAL AFFINITY WITH REFERENCE TO EQUILIBRIUM AND REACTION TRAJECTORIES OF INTERPHASE MASS-TRANSFER

A highly simple and effective new methodology has been proposed to ana lyze the reaction kinetics of non-equilibrium mass transport. Interpha se mass transfer in an evidently non-ideal liquid system has been desc ribed as trajectories on a reaction plane by introducing a logarithmic driving force L(G) which equals to A+/RT, where A+ is newly defined c hemical affinity of a solute. The affinity A+ is referenced not only t o the reaction state but to the equilibrium state, and is different fr om the De Donder's affinity defined solely by a reaction state. The af finity A+ is always smaller than the conventional one. It has also bee n concluded that extractive transfer might occur in a region A+>0. Thi s description of transfer phenomena enables us to treat the reactions directly without the knowledge of rigorous activities of solutes, and is independent to the selection of concentration scale as well as the reference systems for chemical potentials. The affinity A+, i.e. the u pper limit of the reaction trajectories, and the rate of the decrease in the logarithmic driving force have been represented by A+ congruent -to -RT ln xi and -dL(G)/dxi=1/xi using the degree of advancement xi. Consequently, the thermodynamic analysis of reaction trajectories gave insights about the reaction kinetics and its characteristics for two phase systems containing multi-solutes.