Abstract:
The aquation reaction of Co(NH3)5Br2+ was studied kinetically with Ag’, Hg2 *, and Tl3+ as inducing cations. Addition of polyethylene sulphonate, polystyrene sulphonate and polyphosphate markedly enhanced the reaction. The acceleration factor, ranging from 10 to 104, was dependent on the inducing cations, polyclcctrolytes, their concentrations and the concentrations of foreign salts. The enthalpy of activation (AJ/*) and the entropy of activation (AS*) were decreased by addition of polyclcctrolytes in the case of Agh and Hg2*, as has been observed previously, whereas A//* was not influenced and AS* increased in the case of Tl3*. The behaviour of Tl3+ was ascribed to the strong hydration of this cation.
