Excess molar enthalpies and excess molar volumes for (pronane + propan-1-ol) at a temperature of 348.15 K and at pressures of 5, 10, and 15) MPa

Abstract

Excess molar enthalpies H m Eand excess molar volumes V m Ehave been determined for (propane + propan-l-ol) at a temperature T= 348.15 K and pressures p= (5, 10, and 15) MPa. Large and positive H m Ewith a large positive temperature coefficient (excess molar heat capacity) C p,m Eare explained in terms of hydrogen bonds being broken when the propan-1-ol is diluted with the propane. V m Eis negative with a large positive pressure coefficient, suggesting that the propane fits into cavities in the hydrogen-bonded structure of the propan-1-ol, with the number of cavities decreasing with increasing pressure. The V m Efor (propane + propan-1-ol) is intermediate between the values obtained for (ethane + propan-1-ol) and (butane + propan-1-ol). The relative magnitudes of V m Efor these three systems are explained in terms of the relationship of the temperature of measurement to the critical temperature of the alkanes.