Volumetric Properties of Binary System C6H5CH3-DMF at 293.15 K

The densities of binary solution C6H5CH3-DMF (toluene-N,N-dimethylformamide) at 293.15 K were measured by use of the Anton Paar 4500 vibrating-tube densimeter and the dependence of density on molar fraction was fitted by the least-square method with the standard deviation 0.005 kg/m(3), the molar fractions of toluene for the binary solution is from 0 to 1. The apparent molar volumes of C6H5CH3, and DMF in the binary system C6H5CH3-DMF were separately calculated from the density data, and the optimized dependences between apparent molar volumes and molar fractions and mass fractions were also determined respectively by the nonlinear least-square regression, and further more, the limiting partial molar volumes, the standard partial molar volumes and the molar volumes of C6H5CH3, and DMF were also obtained from the functions limits. At the same time, the excess molar volumes for the binary solution were calculated and were fitted by the fourth-order Redlich-Kister equation well, so the Redlich-Kister coefficients and the excess molar volume extremum were obtained. Furthermore, the excess partial molar volumes of C6H5CH3, and DMF were calculated and the dependences of the excess partial molar volumes on molar fractions of C6H5CH3, were fitted with the three-parameter polynomial. The limiting excess partial molar volumes of C6H5CH3, and DMF were also obtained from the polynomials limits as well as from the Redlich-Kister equation coefficients.