Measurement of Some Thermodynamic and Acoustic Properties of Binary Solutions of N,N-Dimethylformamide with 1-Alkanols at 30°C and Comparison with Theories

Abstract

Densities, ρ and ultrasonic velocities, uof binary mixtures of N,N-dimethylformamide (DMF) + methanol, + ethanol, + 1-propanol, + 1-butanol, + 1-pentanol, and + 1-hexanol have been measured at 30°C. The ultrasonic velocities have been compared with values calculated from the free-length theory ( FLT) due to Jacobson and collision-factor theory ( CFT) due to Schaaffs. The measured data are used to compute adiabatic compressibility (ks), deviation in adiabatic compressibility (Δks), intermolecular free length (Lf), molar volume (Vm), and available volume (Va). The excess molar volume ( VmE) and excess free length (LfE) are also evaluated. For all systems, these results were satisfactorily correlated by the Redlich–Kister polynomial. These parameters are used to discuss dissociation of the self-associated 1-alkanol molecules and the formation of aggregates between unlike molecules through C=O...H–O hydrogen bonding.