The analytical models for three different chemical reactions/processes in isothermal-isobaric conditions have been studied. The analysis of the degree of conversion versus time, temperature and initial parameter interdependences enables the kinetics to be approximated by means of many g(alpha) functions or even by the polynomial relationships which include the independent variables time, temperature, their interactions, etc. The evaluation and analysis of the isokinetic effect, if supplemented by some further information, provide the possibility of suggesting the most probable kinetic equation from many g(alpha) values used.