Refractive Indices for the Binary Mixtures of N,N-Dimethylformamide with 2-Butanol and 2-Pentanol at Temperatures 303.15 K, 313.15 K, and 323.15 K

The refractive index values have been measured as a function of composition range at temperatures 303.15 K, 313.15 K, and 323.15 K and at ambient pressure and reported here. From these data, refractive index deviations, ΔnD, excess molar refraction, RmE, were calculated and correlated by the Redlich-Kister-type polynomial equation to derive the coefficients and estimated the standard deviation values. For both systems, ΔnD were found to be both positive and negative. Excess molar refraction, RmE, versus mole fraction, x1, of N,N-dimethylformamide curves were calculated and found as sigmoid at all temperatures. The variation of these properties with composition and temperature of the binary mixtures were discussed in terms of intermolecular interactions