Complexation in Donnan dialysis

We know already from the Donnan equiUhrium condition (Section 4.3.2) that two electrolytes AN and BN separated hy a cation exchange membrane in two solutions 1 and 2 will distribute themselves such that 

The ratio of the total concentrations of species in the two solutions is obtained by using (5.2.159)  

It is known that, without the complexation reaction, there is no selectivity between A and B. It is now clear that the complexation provides considerable selectivity in favor of species A. Most of the above analysis is based on tbe study by Wallace (1967), with one basic underlying assumption, namely that the complexing agent C does not go through the ion exchange membrane. 

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