Abstract

Ostwald (born September 2, 1853, Riga, Latvia, Russia; died April 4, 1932, at his private estate near Leipzig, Germany) almost single-handedly established physical chemistry as an acknowledged academic discipline. In 1909, he was awarded the Nobel Prize in chemistry for his work on catalysis, chemical equilibria, and reaction velocities. Ostwald was graduated in chemistry at the University of Dorpat (now Tartu, Estonia) and appointed professor of chemistry in Riga in 1881, before he moved from Russia to Germany on the chair in physical chemistry at the University of Leipzig in 1887. For about twenty years he made Leipzig an international center of physical chemistry: by establishing an instruction and research laboratory that attracted virtually the whole next generation of physical chemists; by editing the first journal of the field (Zeitschrift für physikalische Chemie); and by writing numerous textbooks. In 1906, he retired from university and devoted the rest of his life to various topics, including the history and philosophy of science, color theory, painting, the writing of textbooks and popular books about science, the international organization of science, and the formation of an artificial language for the international exchange of ideas. Since his master degree thesis in 1876, Ostwald followed the general approach of applying physical measurement and mathematical reasoning to chemical issues. One of his major research topics was the chemical affinity of acids and bases. To that end, he studied the point of equilibrium in reactions systems where two acids in aqueous solution compete with each other for reaction with one base and vice versa. Because chemical analysis would have changed the equilibria, he skillfully adapted the measurement of physical properties to that problem, such as volume, refractive index, and electrical conductivity. From his extensive data he derived for each acid and base a characteristic affinity coefficient independent of the particular acid-base reactions. To understand the different chemical affinities, Ostwald drew on a new, but then hardly accepted and not yet fully developed, theory advanced by Svante Arrhenius. According to this theory of electrolytic dissociation, electrolytes like acids, bases, and salts dissociate in solution into oppositely charged ions to a certain degree, such that at infinite solution dissociation is complete..