Based on two reactions with different behaviour, a comparative study between batch and semibatch reactors performance has been carried out in a glass-jacketed reactor of 51 provided with the measuring, data acquiring and controlling system. The reactions chosen were an acid-base reaction (ethyl acetate saponification), and an oxidation-reduction reaction with a high reaction heat (thiosulfate-peroxide reaction). A first difference was in the method used to establish the kinetic equation. For the acid-base reaction was used an isothermal method based on the conductivity profiles of the solution. For the oxidation reaction was used an adiabatic method based on the measurement of temperatures. This work focuses in the interest to obtain the concentrations of the species in the reactor, by measuring experimentally with different sensors (pH, temperature, etc.) the needed values to get the concentration profiles. For the acid-base reaction it was possible to convert the pH measurements of the reaction solution to concentration values. In the case of the oxidation reaction, the concentration profiles were obtained by measuring only reactor temperature for the adiabatic batch mode of operation, and by simulation in the semibatch mode of operation. The mathematical model was previously validated with temperature profiles obtained experimentally.