In this study, to obtain useful information about the structure of binary mixtures, identify the governing interactions and investigate the influence of alcohol chain length on the structure and nature of interactions in the binary mixtures of toluene (TOL) with 1-pentanol up to 1-decanol, values of second and third virial coefficients for the above binary mixtures were calculated regarding the Peng-Robinson-Stryjek-Vera (PRSV) cubic equation of state. Estimation of the thermodynamic factor for the binary systems was performed by the COSMO-RS model, and results indicate that the considered mixtures exhibit a positive deviation from the Raoult's Law. Besides, the diffusion coefficients for the binary mixtures in the whole composition range were determined regarding the experimental viscosities. Findings demonstrate that the weak dispersion forces (induced dipole-induced dipole attraction) between TOL and 1-alkanol are the most frequent type of interactions, and change with the alcohol chain length. The collected information from the mentioned parameter has been shown that increasing the alcohol chain length reinforces the strength of intermolecular interactions.
