2026, Vol. 7, Issue 1, Part A

This study presents a comprehensive ultrasonic and thermo-acoustic investigation of binary liquid mixtures of ethylbenzoate and 2-methyl-2-propanol over the entire composition range at temperatures 303.15, 308.15, 313.15, and 318.15 K. Experimental measurements of ultrasonic velocity, density, and viscosity were used to evaluate derived parameters such as adiabatic compressibility, molar volume, acoustic impedance, intermolecular free length, internal pressure, and enthalpy. The variation of these parameters with mole fraction and temperature reveals significant non-ideal behavior, indicating strong molecular interactions between the ester and tertiary alcohol molecules. The decrease in compressibility and free length with increasing ethylbenzoate concentration suggests enhanced molecular association and compact molecular packing, while the increase in acoustic impedance and internal pressure supports stronger cohesive forces. Temperature-dependent trends indicate weakening of interactions at elevated temperatures due to increased thermal agitation. The study demonstrates the effectiveness of ultrasonic techniques in elucidating molecular interactions and structural rearrangements in binary liquid mixtures.