The volumetric, optical, and acoustical properties of binary and ternary solutions of (3-amino-1-propanol + N,N-dimethylacetamide), (3-amino-1-propanol + cyclohexanone), (N,N-dimethylacetamide + cyclohexanone), and (3-amino-1-propanol + N,N-dimethylacetamide + cyclohexanone) were investigated in this study. Density (ρ), speed of sound (u), and refractive index ( \({n}_{\text{D}}\) ) were measured across the entire composition range at 298.15, 303.15, 308.15, 313.15, 318.15, and 323.15 K at ambient pressure (81.5 kPa). Excess molar volume \({V}_{\text{m}}^{\text{E}}\) , excess partial molar volume \({\overline{V} }_{i}^{E}\) , deviations in isentropic compressibility \({\Delta k}_{\text{s}}\) , or refractive index \({\Delta n}_{\text{D}},\) were also calculated. Binary mixtures of 3-amino-1-propanol + N,N-dimethylacetamide and N,N-dimethylacetamide + cyclohexanone showed positive \({V}_{\text{m}}^{\text{E}}\) and \({\Delta k}_{\text{s}}\) values, while 3-amino-1-propanol + cyclohexanone exhibited negative values. \({\Delta n}_{\text{D}}\) values were negative for 3-amino-1-propanol + N,N-dimethylacetamide and positive for the other two binary mixtures. \({V}_{\text{m}}^{\text{E}}\) , \({\Delta k}_{\text{s}}\) , and \({\Delta n}_{\text{D}}\) were correlated using the Redlich–Kister and Cibulka equations for binary and ternary mixtures, respectively. The Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state proved to be an effective tool for modeling the density of binary mixtures and ternary mixture. For modeling speed of sound as predictive approach in these mixtures, Schaaff’s Collision Factor Theory and Nomoto’s Relation were employed as theoretical models. Additionally, four mixing rules were successfully applied to predict the refractive index of the studied mixtures. These findings provide insights into intermolecular interactions, molecular size differences, and structural characteristics within the mixtures.
