Figure 4: Isothermal VLE for [x1 chloroform+(1- x1) DIPE] binary system at T=313.15 K. ○, vapor phase; ■ liquid phase. Error bars are hidden within the signs. Figure 5: and 6 show the excess molar Gibbs energy GE and excess molar enthalpy HE, against x1 at 313.15 K and 298.15 K respectively. As shown GE, HE, and VE are negative over the entire concentration range, with a minimum close to x1=0.5.