Investigation of molecular interactions in binary mixture of dimethyl carbonate + N-methylformamide at T = (303.15, 308.15, 313.15 and 318.15) K

Abstract

Density (ρ) and speed of sound (u) of binary liquid mixtures of dimethyl carbonate and N-methylformamide have been determined at T = (303.15, 308.15, 313.15 and 318.15) K over the entire composition range. Experimental data are used to evaluate excess values of molar volume ($V_{\text{m}}^{\text{E}}$), isentropic compressibility ($k_{\text{s}}^{\text{E}}$), isothermal compressibility ($k_{\text{T}}^{\text{E}}$), intermolecular free length ($L_{\text{f}}^{\text{E}}$), acoustic impedance ($Z^{\text{E}}$) and ultrasonic speed ($u^{\text{E}}$). The V^E data in the present investigation were analysed by using Prigogine–Flory–Patterson (PFP) theory. Partial and excess partial molar volumes ($\bar{V}_{{{\text{m}},1}}$, $\bar{V}_{{{\text{m}},2}}$), ($\bar{V}_{{{\text{m}},1}}^{\text{E}}$, $\bar{V}_{{{\text{m}},2}}^{\text{E}}$) and partial and excess partial molar volume of the components at infinite dilution ($\overline{V}_{{{\text{m}},1}}^{\infty }$, $\overline{V}_{{{\text{m}},2}}^{\infty }$), ($\overline{V}_{{{\text{m}},1}}^{{{\text{E}},\infty }}$, $\overline{V}_{{{\text{m}},2}}^{{{\text{E}},\infty }}$) at T = (303.15, 308.15, 313.15, 318.15) K have been calculated. The excess/deviation properties were fitted to Redlich–Kister equation to obtain their coefficients and standard deviations. The present investigation also comprises the acoustic nonlinearity parameter (B/A) in the mixtures and calculation of cohesive energy $\Delta A$, Van der Wall’s constants (a, b) and distance of closest approach (d). Moreover, various semi-empirical relations of ultrasonic speed have been used to correlate the theoretical velocities. FT-IR spectra of pure components and their binaries have been measured at T = 298.15 K.