Kinetics of Malachite Green Fading in Water-ethanol-1-propanol Ternary Mixtures

The rate constant of malachite green (MG(+)) alkaline fading was measured in water-ethanol-1-propanol ternary mixtures. This reaction was studied under pseudo-first-order conditions at 283-303 K. It was observed that the reaction rate constant increases in the presence of different weight percentages of ethanol and 1-propanol. The fundamental rate constants of MG(+) fading in these solutions were obtained by SESMORTAC model. In each series of experiments, concentration of one alcohol was kept constant and the concentration of the second one was changed. It was observed that at constant concentration of one alcohol and variable concentrations of the second one, with increase in temperature, k(1) values increase and this indicates that presence of ethanol (or 1-propanol) increases dissolution of 1-propanol (or ethanol) in the activated complex formed in these solutions. Also, in each zone, fundamental rate constants of reaction at each certain temperature change as k(2) >> k(1) >> k(-1).