Non-steady state approaches have evolved and matured in kinetic research during the last decades. Sophisticated methods enable to get into fine details of chemical processes and their mechanism. At the same time, thermodynamics developed from the classical equilibrium theory to theories not limited by equilibrium, space or time homogeneity. Usually, kinetics and thermodynamics are treated separately as two different, though complementary approaches for description of chemically reacting systems. Within the framework of rational thermodynamics an interesting approach to chemical kinetics was developed. It was proved that the reaction rate is a function of concentration and temperature, which can be approximated by polynomial and this is further simplified using equilibrium criteria. Using this approach, non-traditional rate equations can be derived with new insights on the relations between mechanism, i.e. set of elementary steps, and kinetics. This contribution presents illustrative examples of this approach and discusses its consequences for mechanistic and kinetic interpretation of kinetic experiments and their design. Main points of the rational thermodynamics method include: (a) although it starts with independent reactions, resulting rate equations may also contain other reactions, relevant for the kinetic description; (b) kinetic equilibrium criteria are fulfilled with more general equation than usual Guldberg-Waage with no need for "kinetic" equilibrium constant; (c) reaction mechanism for given set of species is directly proposed. (C) 2004 Elsevier Ltd. All rights reserved.