Kinetics of the Exchange between Silver Iodide and Silver Ions in Aqueous Solution

Using either1l0m Ag-labelled Agl or labelled 0.02 M AgN03 solution, the kinetics of the exchange between the solid and Ag+ ions in solution exhibited a fast initial stage, possibly involving a surface layer of the solid, followed by a slower exchange possibly with Ag+ ions in the lattice. The initial rate increased as the solid/solution ratio increased but this rate was not appreciably altered when the solid was irradiated with visible light prior to the experiment. However, this treatment led to an increase in the rate of the slower step compared to that found for the solid which was not irradiated. The same trend was observed for the solid which was heated before the experiment above the transition temperature to the α-form.