Densities and excess molar volumes of Methanol, Ethanol and<i>N-</i>Propanol in pure Water and in Water + Surf Excel solutions at different temperatures

Abstract

Densities, ρ of the systems Methanol, Ethanol and n-Propanol in water and in 0.05 and 0.1% Surf Excel (SE) solutions in water were measured at temperatures from 303.15 to 323.15 K covering the whole composition range. Excess molar volumes, for the systems were found to be negative and large in magnitude. Densities and excess molar volumes have been plotted against mole fraction of the solutes (X 2). All these properties have been expressed satisfactorily by appropriate polynomials. No appreciable change of the densities and excess molar volumes were observed by the addition of surfactant (0.05 and 0.1%) to the studied systems. An explanation of in terms of hydrophobic hydration and hydrophilic effect of the solutes is offered.