Measurement and Prediction of Thermochemical Properties. Improved Benson-Type Increments for the Estimation of Enthalpies of Vaporization and Standard Enthalpies of Formation of Aliphatic Alcohols

Abstract

This work has been undertaken to revise the group-additivity values necessary for predicting standard enthalpies of formation and vaporization enthalpies of aliphatic alcohols by means of Benson's group-additivity scheme at the reference temperature T = 298.15 K. The database on the molar enthalpies of vaporization has been extended with measurements on some linear alcohols (1-hexanol, 1-heptanol, and 1-nonanol) and branched alkanols (2-hexanol, 5-methyl-3-hexanol, 2-methyl-2-hexanol, 3-ethyl-3-pentanol, 2-ethyl-1-hexanol, 2-methyl-2-heptanol, 3,5,5-trimethyl-1-hexanol, and 2,6-dimethyl-4-heptanol) using the transpiration method. The data were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. A simultaneous compilation and evaluation of data for enthalpies in the liquid and in the gaseous phase together with vaporization enthalpies have been performed, thereby giving a basis for the validation of experimental results. The group-additivity parameters useful in the application of the Benson correlation are presented in tabular form, together with a description of their evaluation.