Excess enthalpy for {x 1-hexanol +(1−x) hexane} at temperatures from 323 to 513 K, and pressures from 3.5 to 15 MPa

This paper reports experimental molar excess enthalpies H m E for {x 1-hexanol + (1−x) hexane}. Measurements have been carried out at temperatures from 323 to 513 K, and pressure from 3.5 to 15 MPa, using a differential heat flux type calorimeter, operated in the flow mode. The pressure dependence of molar excess enthalpy ( ∂ H m E / ∂ p ) T , x has been calculated and compared with values derived from isobaric thermal expansivities αp. Agreement is to within the uncertainty on the measurements. The experimental molar excess enthalpies have been compared with recent UNIFAC calculations. Agreement is reasonable at temperatures up to 373 K, but at 412 and 453 K the calculated values are too high.