The rate of the reaction between potassium bromate and potassium tellurite decreases with an increase in the mole fraction of ethanol in aqueous ethanol mixtures at 308 K. A comparison of the experimental and theoretical values of the radius of the activated complex indicates that a double sphere model is the most suitable shape for the activated state formed in the reaction. Electrostatic and non-electrostatic contributions to the changes in free energy of activation and entropy values are 14.06 kJ/mole, 95.57 kJ/mole and -54.19 J/K/mole in 0.153 mole fraction of ethanol in water. The activation parameters correlates well with the dielectric constants of the media.