Enthalpies of vaporization, and the cohesive and internal energies of 2,2-dimethylpentane, 2,4-dimethylpentane, 2,2,3-trimethylpentane, 2,3,3-trimethylpentane, and 3-ethylpentane

Calorimetric molar enthalpies of vaporization Delta(l)(g)H(m) for five alky l-substituted pentanes were determined over the temperature range (298.15 t o 368.15) K with a typical uncertainty of 0.2 per cent. The measured values , as well as corresponding calculated cohesive and internal energies, were correlated as a function of temperature by using several empirical multipar ameter equations. All the equations fitted well with the data, and some of them were used to extrapolate the data toward the triple and critical boili ng temperatures, and to predict the corresponding property values. (C) 1998 Academic Press.