Variation of excess volumes with temperature for binary mixtures ofp-xylene withn-hexane andn-hexadecane

The variation of the molar volume with temperature from 25 to 50 °C of binary mixtures of p-xylene + n-hexane and p-xylene + n-hexadecane has been measured by a dilatometric method over the complete mole fraction range. From the experimental results we have calculated v^E/T)_p. Literature values of v^E at 25°C together with the integration of v^E/T)_p yield v^E as a function of temperature. The excess volumes of p-xylene + n-hexane at 40 °C and p-xylene + n-hexadecane at 40 and 45 °C have also been measured by a dilatometric method, and the results were compared to those obtained from the integration of . The results from both methods are in excellent agreement within experimental error.The experimental values of are negative for the system p-xylene + n-hexane and positive for p-xylene + n-hexadecane. We have interpreted our experimental results in terms of the order present in p-xylene and n-alkanes.