EXCESS MOLAR ENTHALPIES OF N-OCTANOL N-ALKANE AND ISOPENTANOL N-DODECANE MIXTURES UNDER HIGH-PRESSURE

New high pressure flow calorimetric vessels were designed and made. They were fitted into the Setaram C-80 Calvet microcalorimeter. With the vessels, heats of mixing can be measured from ambient temperature and pressure to 573 K and 20 MPa. The excess molar enthalpies of ethanol-water mixtures at 298.65 K and 0.1, 5 and 10 MPa are in good agreement with those in the literature. Excess molar enthalpies of n-octanol-n-hexane, n-octanol-n-decane, n-octanol-n-dodecane and isopentanol-n-dodecane mixtures were determined at 298.65 K and 0.1 and 10 MPa. They are positive over the entire mole fraction range for the four binary systems.