THERMO-ACOUSTICAL AND EXCESS THERMODYNAMIC STUDIES OF TERNARY LIQUID MIXTURES OF SUBSTITUTED BENZENES IN AQUEOUS MIXED SOLVENT SYSTEMS AT 303.15, 308.15 AND 313.15 K

The observed experimental parameters such as density (ρ), viscosity (η) and ultrasonic velocity (U) of ternaryliquid mixtures of substituted benzenes such as chlorobenzene, bromobenzene, nitrobenzene, ethylbenzene and tolueneadded in the fixed binary solvent mixtures of (ratio 4:2) acetophenone and 1-heptanol at 303.15, 308.15 and 313.15K weredetermined. The observed experimental data have been utilized to evaluate some of the excess thermo acousticalparameters such as adiabatic compressibility (βE), intermolecular free length (LfE), free volume (VfE), internal pressure (πiE),Gibb’s energy (ΔGE), viscosity (ηE) molar volume (VmE)and Grunberg’s Nissan interaction parameter (d). It is eventuallyobserved that weak molecular association between acetophenone and 1-heptanol is through hydrogen bonding andsubstituted benzenes through weak dipole-dipole interactions. The existence of formation of donor – acceptor complexes inthe present study has been identified and promptly discussed. Further, the impact due to the elevation of temperature onthese liquid systems has also been interpreted.