Kinetic and oscillating processes in aqueous solutions.

The first part of the thesis is concerned with oscillating chemical reactions, The Belousov - Zhabotinskii reaction is examined experimentally with respect to the dependence of the frequency of oscillation on temperature for a variety of initial conditions. In another series of experiments, the Belousov - Zhabotinskii reaction is perturbed from its oscillatory phase by the rapid addition of solutions containing either Ce(IV) or Br ions. Both species are intermediates in the reaction scheme. The results are compared with a computer analysis of model schemes for the reaction. In the second part, the kinetics of reaction between the tris(1,10 - phenanthroline) iron (ll) cation and hydroxide ions in water - methyl alcohol and acetone - water mixtures are examined. Here the second order rate constants are determined, The results are analysed in terms of the transfer parameters for the change in chemical potential on going from water to the cosolvent - water mixture. In the case of methyl alcohol - water mixtures the analysis is extended with the aid of an empirical model based upon naphthalene and naphthol, First order rate constants (aquation) are also reported. The final part is concerned with an application of the pair potential model for the interaction between two species in solution. Computation by means of the Hypernetted Chain integral approximation yields values of the osmotic coefficient of a salt in solution. Kinetic data from the literature for the hydrolysis of t-butyl chloride in solutions containing the ion K+ and the tetramethylammonium cation are used to calculate Setchenow coefficients. These values yield information concerning solute - solute interactions in the initial state and the transition state of the hydrolysis.