Thermodynamic, acoustic and transport properties of binary mixture: ethyl benzoate + 2-methyl-1-propanol

Experimental densities (ρ), viscosities (η), and ultrasonic velocities (U) for the binary mixture of ethyl benzoate (component 1) with 2-methyl-1-propanol (component 2) were measured at 303.15, 308.15, 313.15, and 318.15 K over the entire composition range at atmospheric pressure. From these data excess properties—including excess molar volume (V^E), excess adiabatic compressibility (Δβ_ad), excess viscosity (Δη), excess free length (L_f^E), excess internal pressure (π^E), excess acoustic impedance (Z^E), excess Gibbs free energy (G^E), excess enthalpy (H^E) and excess ultrasonic velocity (U^E)—were calculated. Negative values of V^E and Δβ_ad over entire mole fraction ranges indicate strong specific interactions, likely hydrogen bonding, between unlike molecules. The temperature dependence of excess functions reveals enhancement of interaction strength at higher temperatures. Results are discussed in terms of structure–interaction relationships and correlated with Redlich–Kister polynomial fits.