High-Pressure Density Measurements for the Binary System Ethanol + n-Heptane
Résumé
The density of the asymmetrical binary system composed of ethanol and heptane has been measured (630 points) for nine different compositions including the pure compounds at five temperatures in the range (293.15 to 333.15) K and 14 isobars up to 65 MPa with a vibrating-tube densimeter, The experimental uncertainty is estimated to be 0.5 kg·m-3. The isothermal compressibility, the isobaric thermal expansion, and the excess molar volume have been derived from the experimental density data, revealing that a volume expansion occurs for this binary system. The results have been interpreted as due to changes in the molecular free-volume, disruption of the order molecular structure, and the breaking of hydrogen bonds within the self-associating alcohol.