On June 25, 1864, German physicist Walther Hermann Nernst was born. One of the founders of modern physical chemistry he is best known for his theories behind the calculation of chemical affinity as embodied in the third law of thermodynamics, for which he won the 1920 Nobel Prize in chemistry. Nernst contributed to electrochemistry, thermodynamics and solid state physics. He is also known for developing the Nernst equation.
Walter Nernst was educated at the Universities of Zurich, Berlin and Graz. He studied physics and mathematics, and graduated with a thesis on electromotive forces produced by magnetism in heated metal plates in 1887. He accepted an invitation to the Physical Chemistry Chair in Göttingen in 1894 and founded the Institute for Physical Chemistry and Electrochemistry there. In the mid 1900s, Nernst was appointed Professor of Chemistry, later of Physics, in the University of Berlin. He became the Director of the newly-founded Physikalisch-Chemisches Institut in 1924 and remained there until his retirement.
It is believed that Walther Nernst’s early research work in electrochemistry was inspired by Arrhenius’ dissociation theory which put an emphasis on ions in solution. He then elucidated the theory of galvanic cells by assuming an “electrolytic pressure of dissolution” which forces ions from electrodes into solution and which was opposed to the osmotic pressure of the dissolved ions. Nernst also derived equations that defined the conditions by which solids precipitate from saturated solutions.
Walther Nernst’s heat theorem, also known as the Third Law of Thermodynamics, was developed in 1906. The scientist demonstrated that the maximum work obtainable from a process could be calculated from the heat evolved at temperatures close to absolute zero. This work provided a means of determining free energies of chemical reactions from heat measurements. In Berlin, Nernst and his students proceeded to make many important physico-chemical measurements, particularly determinations of specific heats of solids at very low temperatures and of vapour densities at high temperatures. All these were considered from the point of view of quantum theory. In 1918, Nernst established his atom chain reaction theory, assuming that once the energy of a quantum has initiated a reaction in which free atoms are formed, these formed atoms can themselves decompose other molecules with the liberation of more free atoms and so on. The reaction can thus continue for long periods without further outside initiations. For his work in thermochemistry he received the Nobel Prize in Chemistry for 1920. His book ‘Theoretische Chemie vom Standpunkte der Avogadro’schen Regel und der Thermodynamik’ (Theoretical chemistry from the standpoint of Avogadro’s rule and thermodynamics) was first published in 1893 and the tenth edition appeared in 1921 (the fifth English edition in 1923).
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