Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The densities of binary mixtures of acetonitrile (ACN) with formamide (FA), N,N-dimethylformamide (DMF), N-methylacetamide (NMA), and N,N-dimethylacetamide (DMA), including those of pure liquids, over the entire composition range were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15, and 318.15) K and atmospheric pressure. From the experimental data, the excess molar volume, V E m, and partial molar volumes, V m;1 and V m;2, were calculated over whole composition range. The variation of these parameters with composition and temperature of the mixtures has been discussed in terms of molecular interaction in these mixtures. The V E m values were found negative for all the mixtures and at each temperature studied, indicating the presence of specific interactions between ACN and amide molecules. The extent of negative deviations in V E m values follows the order: FA > NMA > DMA > DMF. It is observed that the V E m values depend upon the positions of methyl groups in these amide molecules.