Walther Hermann Nernst (born: June 25, 1864 / died: November 18, 1941)

Nernst was a German chemist and was born in Briesen, Prussia. He studied physics and mathematics at the universities of Zürich, Berlin and Graz. After some work in Leipzig, he founded the Institute for Physical Chemistry and Electrochemistry at Göttingen. In 1920, he received the Nobel Prize in chemistry in recognition of his work in thermochemistry. In 1924, he became director of the Physikalisch-Chemisches Institut in Berlin, a position from which he retired in 1933.

Nernst contributed greatly to electrochemistry, thermodynamics, solid state chemistry and photochemistry. Amongst his most notable discoveries were his "heat theorem", also known as the Third law of thermodynamics and the Nernst equation

In electrochemistry, the Nernst equation (named after German physical chemist Walther Nernst) gives the reversal potential of an electrode E, relative to the standard electrochemical potential, E0, of the electrode couple or, equivalently, of the half cells of a battery  where R is the universal gas constant, T the temperature in Kelvin, z the charge number or valence of the electrode reaction, and a the chemical activities on the reduced and oxidized side, respectively. F is the Faraday constant, equal to 96,485 C mol-1.