Arrhenius

For the Lunar or Martian meteor craters, see Arrhenius (crater).
Svante Arrhenius |
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Svante August Arrhenius (19 February 1859 – 2 October 1927) was a Swedish scientist, originally a physicist, but often referred to as achemist, and one of the founders of the science of physical chemistry. The Arrhenius equation, lunar crater Arrhenius and the Arrhenius Labs at Stockholm University arenamed after him.
[edit]Early years
Arrhenius was born on February 19, 1859 at Vik (also spelled Wik or Wijk), near Uppsala, Sweden, the son of Svante Gustav and Carolina Thunberg Arrhenius. His father had been a land surveyor for Uppsala University, moving up to a supervisory position. At the age of three, Arrhenius taught himself to read without the encouragement of his parents, and by watchinghis father's addition of numbers in his account books, became an arithmetical prodigy. In later life, Arrhenius enjoyed using masses of data to discover mathematical relationships and laws.
At age 8, he entered the local cathedral school, starting in the fifth grade, distinguishing himself in physics and mathematics, and graduating as the youngest and most able student in 1876.
At the Universityof Uppsala, he was unsatisfied with the chief instructor of physics and the only faculty member who could have supervised him in chemistry, Per Teodor Cleve, so he left to study at the Physical Institute of the Swedish Academy of Sciences in Stockholm under the physicist Erik Edlund in 1881. His work focused on the conductivities of electrolytes. In 1884, based on this work, he submitted a150-page dissertation on electrolytic conductivity to Uppsala for the doctorate. It did not impress the professors, like Per Teodor Cleve, and he received a fourth class degree, but upon his defence it was reclassified as third class. Later, extensions of this very work would earn him the Nobel Prize in Chemistry.
There were 56 theses put forth in the 1884 dissertation, and most would still be acceptedtoday unchanged or with minor modifications. The most important idea in the dissertation was his explanation of the fact that neither pure salts nor pure water is a conductor, but solutions of salts in water are.
Arrhenius' explanation was that in forming a solution, the salt dissociates into charged particles (which Michael Faraday had given the name ions many years earlier). Faraday's beliefhad been that ions were produced in the process of electrolysis; Arrhenius proposed that, even in the absence of an electric current, solutions of salts contained ions. He thus proposed that chemical reactions in solution were reactions between ions.
The dissertation was not very impressive to the professors at Uppsala, but Arrhenius sent it to a number of scientists in Europe who were developingthe new science of physical chemistry, such as Rudolf Clausius, Wilhelm Ostwald, and J. H. van 't Hoff. They were far more impressed, and Ostwald even came to Uppsala to persuade Arrhenius to join his research team. Arrhenius declined, however, as he preferred to stay in Sweden for a while (his father was very ill and would die in 1885) and had received an appointment at Uppsala.
In an extensionof his ionic theory Arrhenius proposed definitions for acids and bases, in 1884. He believed that acids were substances which produce hydrogen ions in solution and that bases were substances which produce hydroxide ions in solution.
[edit]Middle period
Arrhenius next received a travel grant from the Swedish Academy of Sciences, which enabled him to study with Ostwald in Riga (now in Latvia),with Friedrich Kohlrausch in Würzburg, Germany, with Ludwig Boltzmann in Graz, Austria, and with van 't Hoff in Amsterdam.
In 1889 Arrhenius explained the fact that most reactions require added heat energy to proceed by formulating the concept of activation energy, an energy barrier that must be overcome before two molecules will react. The Arrhenius equation gives the quantitative basis of the...