(1) For the discussion of the general trend of isomerization reactions of unsaturated hydrocarbons, the free energy equations as a function of temperature, convenient for practical calculations, are derived, based on some of the more recent data available. (2) With the aid of these simple free energy equations, ΔF’s at 0°, 25°, 100°, 200° and 300°C. are computed and tabulated. (3) Some correlations in connection with these thermodynamical calculations for isomerization reactions are presented. (4) In general, isomerization reactions of hydrocarbons with a few exceptions are favoured thermodynamically at a lower temperature, as found in the case of saturated hydrocarbons. (5) As we have already stated in the case of saturated hydrocarbons, isomerization reactions from those of simpler structure to the more complicated and branched are favoured thermodynamically, more or less, at a lower temperature. (6) As in the case of saturated hydrocarbons, the conclusion given by Rossini that isomeric form is more stable than the normal form is also found to be reasonable, as far as our calculation indicates.
(1) The condensation coefficient (α) of iodine and other easily analysable vapours at the surface of various solvents were measured by newly deviced method. The orders of the magnitude of them are 10−3∼10−5 at room temperature. (2) A solubility formula including α was derived kinetically, in which the effects of surface adsorption and compound formation were taken into considerations, and an explanation of the mechanism of evaporation and dissolution was tried by comparing with solubility data.