Standard heats of solution at 25°C are reported for squalane in mixtures of n-heptane + iso-octane and in binary mixtures of chloroform, carbon tetrachloride, and cyclohexane; for cyclohexane in chloroform + carbon tetrachloride; and for chloroform in carbon tetrachloride + cyclohexane. General equations based on simple mixing models are developed for the excess thermodynamic properties of a solute at infinite dilution in a binary solvent. For the systems studied, mixing equations based on volume fractions give better agreement than those based on mole fractions, and the agreement is further improved by the use of weighting factors based on the properties of the solute + solvent binary systems. © 1975 Plenum Publishing Corporation.