Physico-chemical studies of alcohol-water binary systems at different temperatures

ABSTRACT

Density and viscosity measurements carried out in aqueous binary mixtures of n-propanol, and iso-propanol at different temperatures. The volume contraction either [Delta] or [Delta V] for these systems revealed occurrence of a minimum at X [alc approximately 0.31 indicates the probability of the existence of [1 alcohol 2 water] molecular complex. Calculation of the deviation of the molar viscosity [Delta neta [M12]] for both mixtures at different compositions gives negative values with a minimum at the same mole fraction of alcohol which supports the existence of the suggested molecular complex. The Eyring's equation for the temperature dependence of viscosity is used to predict enthalpy [Delta H degree] and entropy [Delta S degree] of activation for the flow process. The conclusion is that the behaviour of each alcohol when mixed with water is dependent mainly on its structure