Lars Onsager (1903-1976) made significant contributions to chemistry, including his developments in the Debye-Hückel theory of electrolytic dissociation and his work with non-reversable systems. He received the 1968 Nobel Prize in Chemistry.

Born in Norway, Lars Onsager received his early education there before coming to the United States in 1928 to do graduate work at Yale University. After receiving his Ph.D. in theoretical chemistry he stayed on at Yale and ultimately spent nearly all of his academic career at that institution. Onsager's first important contribution to chemical theory came in 1926 when he showed how improvements could be made in the Debye-Hückel theory of electrolytic dissociation. His later (and probably more significant) work involved non-reversible systems --systems in which differences in pressure, temperature, or some other factor are an important consideration. For his contributions in this field, Onsager received a number of important awards including the...