Physical and excess properties of binary and ternary mixtures of 1,1-dimethylethoxy-butane, methanol, ethanol and water at 298.15 K

The ternary systems 1,1-dimethylethoxy-butane (BTBE) + methanol + water and BTBE + ethanol + water have large heterogeneous zones. Experimental densities, refractive indices and speeds of sound have been measured at 298.15 K for mixtures of these systems within the homogeneous zone, and also for methanol + BTBE and ethanol + BTBE binary systems over the entire range of compositions. Excess molar volumes and molar refraction and isentropic compressibility changes of mixing were calculated from the experimental physical properties and were satisfactorily correlated with the corresponding composition data using the Redlich–Kister polynomial. Fitted coefficients and mean standard deviations of correlations have been reported.