In this paper, the authors will describe an acidic sulfate medium in which various concentrations of the possible Ce(IV) species can be prescribed. Secondly, they present the computations-based on simultaneous solutions of various equilibrium of the concentration distributed of the sulfato and hydroxo species of Ce(IV). Lastly, the optimum planning of a kinetic study of a Ce(IV)-reductant system, based on the quantitative description of the medium is suggested.