The History of Ozone. v. Formation of Ozone from Oxygen at High Temperatures (1)

In his 1884 book on the principles of mobile equilibria, van’t Hoff (2) presented the generalization that, in an equilibrium system, an elevation of temperature would favor the endothermic reaction. Twenty years later, Nernst, as part of his efforts in developing the third law of thermodynamics (3), derived an expression for calculating the equilibrium constant for a reaction at any temperature. These ideas were expressed specifically in relation to ozone in a 1903 lecture by Nernst at the University of Göttingen as reported by Kremann (4). In agreement with van’t Hoff, the formation of ozone was favored by increasing temperature. Nernst considered the equilibrium between two molecules of ozone and three of oxygen (rxn 1) to be composed of equilibria between ozone and oxygen plus atomic oxygen (rxn 2) and between oxygen and 2 atoms of oxygen (rxn 3); rxn 4 was not considered: