Thermophysical properties of ternary liquid mixture of diisopropyl ether (1) + ethanol (2) + n-heptane (3): Measurement and correlation

Abstract Densities (ρ), speeds of sound (u) and refractive indices (n) of system containing diisopropyl ether, ethanol and n-heptane were measured at temperature 298.15 K to 318.15 K and at pressure 0.1 MPa. The values of excess molar volume (VmE), excess speed of sound (uE), deviation in refractive index (Δn), excess isentropic compressibility (κsE), excess intermolecular free length (LfE), and excess available volume (VaE) of the system were calculated using measured data of densities, speeds of sound and refractive indices. The VmE values were fitted to the Singh, Cibulka and Nagata equations. Several analytical models like Rastogi model, Kohler model, Tsao-Smith model, Radojkovic model and Jacob-Fitzner model were applied to estimate VmE values. The values of uE, κsE, LfE, VaE and Δn were also fitted to the Singh equation. Different correlations and models were applied for estimation of sound velocity and refractive index values.