ScienceWeek

SVANTE ARRHENIUS (1859-1927)

The Arrhenius theory of electrolytes, introduced in 1887 by Arrhenius when he was a graduate student, proposed that acids are substances that dissociate in water to yield electrically charged atoms or molecules, called "ions", one of which is a hydrogen ion (H+), and that bases ionize in water to yield hydroxide ions (OH-). It is now known that the hydrogen ion cannot exist alone in water solution, but that instead it exists in a combined state with a water molecule as the hydronium ion. Although these ideas of Arrhenius were scorned by his teachers, the Arrhenius theory of electrolytes came to form the basis of 20th century solution chemistry.

The following points are made by J. Van Houten (J. Chem. Ed. 2002 79:21):

1) Svante Arrhenius won the Nobel Prize in 1903 for his electrolytic theory of dissociation, which extended van't Hoff's ideas about the nature of molecules in solution into the realm of aqueous salts, acids, and bases. However, Arrhenius's ionic dissociation theory was initially considered controversial, and his 1884 doctoral dissertation, "Investigations on the Galvanic Conductivity of Electrolytes", received the lowest possible grade, "not without merit", at the University of Uppsala.

2) Arrhenius was the first Swede to win a Nobel Prize in any field. Although he was recognized for his electrolytic theory of dissociation, his name is most familiar to modern chemistry students because of its association with a definition of acids and bases, and through the equation that relates reaction rate constants to activation energies and temperature. Both contributions of Arrhenius, the electrolytic theory and the activation energy concept, have been important in the development of modern concepts of chemical dynamics.

3) Arrhenius studied with Jacobus van't Hoff (1852-1911) (Nobel Prize 1901) and with Wilhelm Ostwald (1853-1932) (Nobel Prize 1909). Arrhenius was actually considered for the physics as well as for the chemistry prize in 1903. In 1905, The Royal Swedish Academy of Sciences established a Nobel Institute for Physical Chemistry with Arrhenius as its first chief. Arrhenius went on to become chairman of the Nobel Committee for Physics of the Royal Swedish Academy of Sciences, and in that capacity gave the presentation speech for Albert Einstein in 1921 and for Niels Bohr in 1922.