Measurement and Modeling of Excess Molar Volume and Excess Enthalpy of n-Tridecane or n-Tetradecane with Decalin by Application of PFP Theory

The experimental measurement of density and enthalpy of mixture for two binary liquid mixtures of n-tridecane or n-tetradecane with decalin was reported in this paper. The measurements were conducted at a temperature range of 293.15–323.15 K and at 303.15 K using calorimeter C80. The mixtures were analyzed at various proportions, including the entire composition range and dilute solutions. The excess molar volume (V^E) and excess molar enthalpy (H^E) of mixtures were calculated and fitted using the Redlich–Kister equation. The paper observed the expansion phenomenon for the V^E at all temperatures, including over the entire composition range and dilute solutions. Additionally, the H^E exhibited endothermic behavior at the studied temperature range and composition range. The Prigogine–Flory–Patterson (PFP) theory was utilized to predict both thermodynamic properties, namely the V^E and H^E. The results obtained using the PFP theory were compared with those obtained using the Treszczanowicz and Benson association (TB) model for V^E and with the NRTL, Wilson, and Flory models for H^E. The PFP model, which employed a single-fitted parameter to describe V^E, demonstrated satisfactory performance in predicting V^E. Conversely, the Treszczanowicz and Benson association (TB) model yielded relatively poor results in fitting V^E. However, the NRTL, Wilson, PFP, and Flory models exhibited good performance in predicting H^E.