Quadrupole coupling in (carbon dioxide + dioxane)(g). The excess molar enthalpy and second virial cross-coefficient of (dioxane + carbon dioxide or propane)(g)

✍ Scribed by C.J. Wormald; P.W. Johnson

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 91 KB
• Volume: 31
• Category: Article
• ISSN: 0021-9614
• DOI: 10.1006/jcht.1999.0521

✦ Synopsis

A flow-mixing calorimeter has been used to measure the excess molar enthalpy H E m ( p o ) of (carbon dioxide + dioxane)(g) and (propane + dioxane)(g) at standard atmospheric pressure ( p o ) = 0.101325 MPa over the temperature range T = (373.2 to 433.2) K. The measurements on (propane + dioxane) were fitted by using (1

. This value was used to calculate H E m for (carbon dioxide + dioxane) but the measured values were found to be less positive than predicted. The difference was attributed to quadrupole-quadrupole coupling energy and this was estimated by assuming a quasi-chemical model which, for the carbon dioxide-dioxane interaction, yielded a value of the equilibrium constant K 12 (298.15 K) = 0.126 MPa -1 and an enthalpy of association H 12 = -(8.4 ± 2) kJ • mol -1 . Second virial cross-coefficients have been derived from the measurements.