Ostwald, (Friedrich) Wilhelm (1853-1932)

Latvian-born German chemist who devised the Ostwald process (the oxidation of ammonia over a platinum catalyst to give nitric acid). His work on catalysts laid the foundations of the petrochemical industry. He was awarded the Nobel Prize for Chemistry in 1909 for his work in catalysis, and the principles of equilibria and rates of reaction.

Ostwald was born in Riga and studied at the University of Dorpat (Tartu) in Estonia. He was professor at Riga 1881-87 and at Leipzig 1887-1906, and was from 1898 the first director of Leipzig's Physicochemical Institute.

In 1888, he proposed the Ostwald dilution law, which relates the degree of dissociation of an electrolyte, α, to its total concentration c expressed in moles per litre (dm3). It states that:

k = α2c/(1 -α)

The constant, k, neglects the activity coefficient and is therefore not a true thermodynamic constant K. The equation is important historically because it was the form in which the law of mass action was first applied to solutions of weak organic acids and bases. Ostwald then worked on the theory of acid-base indicators.

From 1909 Ostwald became interested in the methodology and organizational aspects of science, in a world language, internationalism, and pacifism. He also built a laboratory for colour research.