Solution behavior of {(formamide/N-methylformamide/N,N-dimethylformamide) + CsCl + water} ternary systems at multiple temperatures

•Formamide/N-methylformamide/N,N-dimethylformamide + CsCl + water ternary systems.•The isothermal solubilities are correlated by the NRTL model and UNIQUAC model.•The mean activity coefficients are obtained by the UNIQUAC model.

In this work, the isothermal solubility, density and refractive index of the {formamide (FA)/N-methylformamide (NMF)/N,N-dimethylformamide (DMF) + CsCl + water} ternary systems are determined at T = (288.15, 298.15 and 308.15) K and 0.1 MPa. The isothermal solubility is correlated by the NRTL model and UNIQUAC model. As the temperature is considered, a linear fitting equation of temperature is adopted here to fit the density and refractive index. The turbidity instrument is employed to investigate the solubility of the salt at multiple temperatures. Moreover, the related thermodynamic functions derived from the Van’t Hoff equation were calculated. The mean activity coefficients of the (FA/NMF/DMF + CsCl + H2O) systems at T = (288.15, 298.15 and 308.15) K have been obtained as a combination of the thermodynamics and phase equilibrium through the UNIQUAC model.

Graphical abstractSolubility, density, and refractive index of the FA/NMF/DMF (1) + CsCl (2) + H2O (3) systems at multiple temperatures were determined. The NRTL, UNIQUAC and Van’t Hoffe equation were employed to obtain the thermodynamic properties of the system.Figure optionsDownload full-size imageDownload as PowerPoint slide