Abstract: The binary systems composed of alcohols and other organic solvents, both in theory and in practice, are important to us. Researches for the thermodynamic properties of these systems can not only provide reliable data and empirical rules for science and technology, but also help to investigate the states, structures of the solutes and sol- vent in solution as well as their interactions. In this series, by measuring the excess thermodynamic functions (such as the heats of mixing, volume changes on mixing and excess free energies) for the systems of C_1 to C_(10) alcohls with various organic solvents we will explore the influence of the size and structure of the molecules present in mixtures on excess termodynamic functions, and further discuss these effects from theories of solution.
In the first part, molar excess enthalpies of methanol+, ethanol+, n-propanol+, n-butanol+and n-amyl alcohol+benzene at 298.15 K and under normal pressure have been measured with a Picker flow microcalorimeter. The results obtained was slightly higher than those of the available literature data. Maximum values of H~E for these systems are situated on 0.30—0.33 mole fraction of alcohols. Molar excess enthalpies of the titled systems increase with chain length of the alcohols, whereas the difference between two neighbouring alcohols decrease with increasing of the number of carbon atoms in alcohol.