Theoretical analysis of activation parameters in mixed solvents involving various chemical equilibria. Reaction of ethyl iodide with bromide ion in N-methylacetamide-acetonitrile and N-methylacetamide–N,N-dimethylacetamide mixtures

Abstract

A theoretical equation has been developed for an activity coefficient of a solute dissolved in a mixed solvent based on the assumption of ideal associated mixtures, where three types of chemical equilibria proceed simultaneously, namely two types of equilibria between a solute and a further chemical species in a binary mixed solvent, and an association equilibria between the two component solvents. The derived equation was transformed into further theoretical equations for the rate constants and activation parameters for the ethyl iodide plus bromide ion reaction. The rate constants and activation parameters for the reaction determined in N-methylacetamide–acetonitrile and in N-methylacetamide–N,N-dimethylacetamide mixtures have been analysed by applying these equations.