Since the rate of the inhibitor supply into the solution was constant, the g-DEIS impedance parameters in the solutions with and without the inhibitor can be correlated with the instant concentration of the molybdate inhibitor in the examined solutions at a given time point. Therefore, inhibition effectiveness, IE, can also be estimated from the g-DEIS data using Eq. ( ) . The calculated values are listed in Fig. . Opposite to polarization ( kinetics. The g-DEIS data also allows to estimate these parameters based on the construction of adsorption isotherms . Several types of adsorption isotherms can be used to calculate the adsorption Gibbs energy 0 G  and the adsorption equilibrium constant Kads . These calculations require the knowledge of the surface coverage by the inhibitor, θ. Assuming that the complete coverage of the surface gives a 100% reduction in the corrosion rate, it can be taken that θ corresponds to the IE of the inhibitor, calculated above for the g-DEIS data by Eq. ( ) (Fig. ).