Speed of sound (U), density (rho) and viscosity (eta) values for the equimolar mixtures of (methyl benzoate + 1-propanol) and (ethyl benzoate + 1-propanol) with 1-butanol/1-pentanol including those of pure liquids were measured over the entire mole fraction range at T = 303.15 K. Using these experimentally determined values, various thermo-acoustic parameters such as excess isentropic compressibility (K-s(E)), excess molar volume (V-E) and excess free length (L-f(E)), excess Gibbs free energy (Delta G(*E)) and excess enthalpy (H-E) have been calculated. The excess functions have been fitted to the Redlich-Kister type polynomial equation. The deviations for excess thermo-acoustic parameters have been explained on the basis of the intermolecular interactions present in these binary mixtures. The experimentally determined values of speed of sound have been used to check the applicability of different speed of sound models of Nomoto, Impedance relation, Van Dael and Vangeel, Junjie's, free length theory and Rao's relation. Viscosity results have been used to test the applicability of standard viscosity models of Grunberg-Nissan, Hind-Mc Laughlin, Katti-Chaudhary, Heric and Brewer, Frenkel and Tamura and Kurata at various temperatures for the binary liquid systems under study. (C) 2013 Elsevier Ltd. All rights reserved.