There are some very striking similarities between equilibrium and kinetics of reactions, including temperature effects, salt effects, and rate-equilibrium relationships. Transition state theory provides a basis for understanding these similarities. The various roles of the solvents in chemical reactions have been made clear by extending the theory.
Sometimes the reaction in solution indicates a quite complex behavior. A thermodynamic approach which includes a splitting of the change in activation parameters into contributions from the initial and the transition states, is invaluable for a detailed understanding of molecular processes in solution. Recent works by the author have been presented as an example.