New aspects on the cohesion of simple compounds. II

In the preceding paper it is shown theoretically, that the sum of the contributions of the Debye and Keesom energy to the boiling point of halogenated methane, ethane and ethene derivatives should be about a constant. In this paper it is shown, how far this holds experimentally. An up to date complete list of the boiling points of the ethane and ethene derivatives is given. For the methane derivatives only those are given which have not been published before by van Arkel and coworkers. The boiling points of all these compounds are split up into several parts, according to the different kinds of cohesion effects. Special methods are developed for the 1.1‐ and cis‐ and trans‐1.2‐isomers C₂H₂X₂. The “anomalies” of the boiling points of the C₂H₂I₂ and C₂H₂ClI can easily be understood on the basis of the new theory.