Formation constant. See

From the overall formation constants (see Equations 17-5 through 17-8), the concentrations of the complexes can be expressed in terms of the free metal concentration [M], to give... 

The parameter Kp can be estimated from the Eigen Fuoss model, which was originally derived to estimate the ion pair formation constant (see section 3.10). One of the ions is assumed to have a radius a which is equal to the distance between the reactants at the reaction site. Other ions of the redox couple which are within or on a sphere of radius a can react. The estimate of Kp also takes into consideration any electrostatic work done to bring the reactants to the reaction site. The equation for Kp in units of M is... 

Nici Nicij were assumed to be nearly constant with increasing MCI concentration, and were included in the reported formation constants (see discussion on [89BJE]). The method used by the author is more appropriate to the study of weak complex formation than the constant ionic medium principle if very high and varying concentrations of a complex-forming anion is used, (see discussion on [89BJE]). Nevertheless, the formation constants determined in this way are not compatible with the log P° values extracted from the SIT analysis... 

The lines in Fig. 9 give the cation adsorption behavior at a solution-solid interface as a function of constant pH with total cation mole fraction, cJj, and total surface-site mole fraction, cj, held constant. The dominant trend in cation adsorption is that as pH increases so does cation adsorption because the fraction of anionic surface sites increases with increasing pH. The role of adsorption constants can be seen to be very significant. Adsorption occurs at a lower pH as the p l P a2 increase and vice versa for the Since the former are defined as disassociation constants [see Eqs (14) and (19)] while the latter is an association or formation constant [see Eq. (77)], the different relationship of these adsorption constants with adsorbed cation mole fraction is not surprising. 

The K values are cumulative or overall formation constants (see page 1154). 

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