We present experimental data of speed of sound, refractive index on mixing and density for the binaries of propyl acetate+(toluene, ethylbenzene, p-xylene, isopropylbenzene, butylbenzene, isobutylbenzene, mesitylene, or t-butylbenzene) at T=298.15 K and 1 atm, and the corresponding computed derived magnitudes (change of isentropic compressibility, change of refractive index on mixing, and excess molar volume). The mixtures show a clear expansive tendency for the highest molar weight compounds, and the steric hindrance role of the aromatic chemicals was analyzed to the light of the non ideality on mixing. Values of physical properties were compared with the results obtained by theoretical estimation procedures.