Second virial coefficients of benzene and cyclohexane from measurements of the excess molar enthalpy of (0.5N2+ 0.5C6H6) and (0.5N2+ 0.5C6H12) from 333.2 K to 433.2 K

✍ Scribed by C.J. Wormald; E.J. Lewis; A.J. Terry

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 329 KB
• Volume: 28
• Category: Article
• ISSN: 0021-9614
• DOI: 10.1006/jcht.1996.0004

✦ Synopsis

Values of the second virial coefficient B of benzene and cyclohexane have been obtained from measurements of the excess molar enthalpy H E m of {yN2 + (1y)C6H6} and {yN2+(1-y)C6H12} measured at standard atmospheric pressure over the temperature range 333.2 to 433.2 K. In a hypothetical mixture of an ideal gas with benzene or cyclohexane a measurement of H E m is equivalent to a measurement of the isothermal Joule-Thomson coefficient f22 of the hydrocarbon. In a mixture of the nearly ideal gas nitrogen with hydrocarbon, f11 for nitrogen is small. The cross term isothermal Joule-Thomson coefficient f12 is also small and can be calculated with adequate accuracy using an established combining rule. Potential parameters which fit B22 and f22 for the hydrocarbon can then be calculated from the H E m measurements. It is shown that the H E m measurements yield values of f22 for benzene and cyclohexane which are in good agreement with values obtained from throttling experiments, and that values of B22 agree well with those obtained from (p, rn, T ). It is suggested that H E m measurements on these mixtures might be useful for testing the performance of mixing calorimeters, and empirical equations which fit the measurements at mole fraction y=0.5 are given.