Johannes Nicolaus Brønsted

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DANISH CHEMIST
1879–1947

Johannes Nicolaus Brønsted was a physical chemist whose work resulted in a new theory of acids and bases. He was born in the town of Varde in Jutland (Denmark), where his father was an engineer for the Danish Heath Society. His mother died shortly after his birth. When his father died in 1893, young Brønsted relocated to Copenhagen, where he was admitted to the old Latin school (high school), the Metropolitanskolen. He passed the school's final examinations in 1897.

Brønsted studied chemistry at the University of Copenhagen. He received a master of science degree in 1902 and a doctorate degree in 1908. After receiving temporary appointments at the University of Copenhagen, he became an assistant professor there in 1905, and full professor in 1908. Brønsted studied chemical affinity, electrolytes, isotope separation, reaction kinetics, thermodynamics, and acid-base catalysis .

On May 4, 1923, the Dutch chemical journal Receueil des Travaux Chimiques des Pays-Bas (42:718) received a paper from Brønsted on existing concepts of acids and bases. In this paper Brønsted demonstrated how useful it was to define an acid as a proton donor and a base as a proton acceptor. In the Brønsted scheme, acid-base reactions are proton transfer reactions. Every acid is related to a conjugate base, and every base to a conjugate acid. Also in this paper he pointed out that there is an analogy between the proton transfer that is characteristic of acid-base reactions and the electron transfer that is characteristic of oxidation -reduction reactions.

On January 19, 1923, an article by Thomas Martin Lowry (1874–1936) was published in the English journal Chemistry and Industry , in which the idea of proton transfer between acids and bases was launched. In spite of this, Brønsted's theorizing work has been recognized, and the terms Brønsted acid and Brønsted base have had wide usage.

SEE ALSO Acid-Base Chemistry .

Ole Bostrup

Bibliography

Brock, William (1993). The Norton History of Chemistry. New York: Norton.

Greenberg, Arthur (2000). A Chemical History Tour. New York: Wiley.