Refractive properties and internal pressures of binary mixtures of octan-1-ol with chloroform, 1,2-dichloroethane and 1,1,2,2-tetrachloroethane at 298.15 and 308.15Â K

Refractive indices (nD) of binary mixtures of octan-1-ol with chloroform, 1,2-dichloroethane (DCE) and 1,1,2,2-tetrachloroethane (TCE) have been determined at 298.15 and 308.15 K and at atmospheric pressure for the whole composition range. Absolute synergies of refractive index (ΔnD), relative synergies of refractive index (In), reduced molar free volumes (Vm/Rm), Eykman's constants (Cm), molar refractions (Rm), internal pressures (Pint), molecular radii (rm) and the deviations of reduced molar free volumes Δ(Vm/Rm), Eykman's constants (ΔCm) and molecular radii (Δrm) have been determined from the experimental refractive index and density data at 298.15 and 308.15 K. These quantities have been fitted to the Redlich-Kister polynomial equation and the results analyzed in terms of molecular interactions and structural effects. Refractive indices have been compared with those predicted by several mixing rules: Lorentz-Lorenz, Gladstone-Dale, Arago-Biot, Wiener, Heller, Laplace and Eykman. Finally, a linear relation between van der Waal's parameter (b) and molar refraction (Rm) has been provided and the refractive indices have been predicted in terms of root mean square deviations.