A Century of Chemical Dynamics Traced through the Nobel Prizes. 1903: Svante Arrhenius

This, the second of a series of thirteen articles on Nobel Laureates in chemical dynamics, features the work of Svante Arrhenius, who won the Nobel Prize in 1902 for his electrolytic theory of dissociation. The first article in this series, which appeared in the December 2001 issue of this Journal discussed Jacobus van't Hoff's contribution to our understanding of the nature of molecules in solution and to the study of solution-phase reaction dynamics. Arrhenius's electrolytic dissociation theory extended van't Hoff's ideas about the nature of molecules in solution into the realm of aqueous salts and acids and bases. Not only did this allow for correction of the van't Hoff equation as applied to electrolytes (the so-called van't Hoff i-factor), but it also showed how van't Hoff's principles of chemical dynamics could be applied to ionic solutions. The studies of catalysis by Ostwald (Nobel 1909, to be discussed in the February 2002 issue of this Journal in the next essay in this series) were guided by the work of van't Hoff and Arrhenius, both of whom had worked with Ostwald. Although it was not mentioned specifically in his Nobel presentation, the well-known Arrhenius equation relating reaction rate constants to activation energies and temperature is fundamental to all subsequent studies of reaction energetics and catalysis, and no modern discussion of chemical dynamics could begin without it. Arrhenius is best remembered today by teachers and students of chemistry because the definition of acids and bases and also the equation relating reaction rate constants to temperature through the activation energy that are both named for him.