THERMODYNAMIC PROPERTIES OF ALKENES (MONO-OLEFINS LARGER THAN C-4)

The thermodynamic properties of the mono-olefins with carbon numbers greater than C4 were reviewed. Properties included critical properties, vapor pressures, densities, second virial coefficients, enthalpies of vaporization, heat capacities, and enthalpies of combustion. Enthalpies of formation for the liquid, gas, and ideal-gas state at 298.15 K were calculated for 47 compounds based on the experimental values. Sufficient experimental information was available to allow the calculation of entropies, enthalpies, and Gibbs energies for the ideal-gas state (over approximately a 100 K range near 250 K to 400 K) for 14 compounds. Comparisons were made with experimental isomerization equilibria, isomerization enthalpies, and group-contribution estimates for enthalpies of formation and entropies. ''Gaps'' in the available data were identified and recommendations for additional experiments are made. Evidence for errors in several of the original experimental results is presented, and revised values are suggested.