Vapor Pressures and Vaporization Enthalpies of the n-Alkanes from C₂₁ to C₃₀ at T = 298.15 K by Correlation Gas Chromatography

The temperature dependence of gas chromatographic retention times for n -heptadecane to n -triacontane is reported. These data are used to evaluate the vaporization enthalpies of these compounds at T = 298.15 K, and a protocol is described that provides vapor pressures of these n -alkanes from T = 298.15 to 575 K. The vapor pressure and vaporization enthalpy results obtained are compared with existing literature data where possible and found to be internally consistent. Sublimation enthalpies for n -C 17 to n -C 30 are calculated by combining vaporization enthalpies with fusion enthalpies and are compared when possible to direct measurements.