Kinetics of differential ion-exchange processes in a finite solution volume

✍ Scribed by K. Bunzl

• Publisher: Elsevier Science
• Year: 1974
• Tongue: English
• Weight: 845 KB
• Volume: 102
• Category: Article
• ISSN: 1873-3778
• DOI: 10.1016/s0021-9673(01)85444-3

✦ Synopsis

Rate equations

are given for film diffusion-controlled, differentially small ion-exchange processes in a finite solution volume. Two possibilities of performing differential ion-exchange reactions were considered:

(1) reactions in which, independent of the initial ionic composition of the sample, the same small amount of counter ions is added, and (2) reactions in which, depending on the initial ionic composition of the sample, the amount of counter ions added is adjusted so as always to yield the same differential conversion of the sample. The theory shows in which way the rate of a differential ion-exchange process, which may involve ions of arbitrary valency, depends on the diffusion coefficients of the ions in the film, on the selectivity of the ion exchanger, on the initial ionic composition of the sample and on the extent of each differential reaction. It is shown that at any given initial ionic composition of the sample, the ratio of the initial rate of the forward to that of the corresponding reverse differential ion-exchange process is independent of the diffusion coefficients of the ions.