In thermodynamics, chemical thermodynamics is the energetic and entropic study of physical processes or chemical reactions. [1] The central aspects of study in chemical thermodynamics are the initial and final states of the process or reaction. If the energy and entropy are known, with respect to appropriate reference points, for all values of pressure, volume, and temperature to be covered in the investigation, then the thermodynamic examination can be a complete one. [1] In this sence, chemical thermodynamics is the study of energy, entropy, and equilibrium in chemical systems. [4] English physical chemist Brian Smith, gives an excellent description on the wondrous yet cautious intrigue many have with their first encounter with chemical thermodynamics: [5]

“The first time I heard about chemical thermodynamics was when a second-year undergraduate brought me the news early in my freshman year. He told me a spine-chilling story of endless lectures with almost three-hundred numbered equations, all of which, it appeared, had to be committed to memory and reproduced in exactly the same form in subsequent examinations. Not only did these equations contain all the normal algebraic symbols but in addition they were liberally sprinkled with stars, daggers, and circles so as to stretch even the most powerful of minds.”

Chemical thermodynamics is generally considered the most difficult subject in all of science.

History
German physical chemist August Horstmann was the first to have done work in chemical thermodynamics. In circa 1865, he began to study the works of Rudolf Clausius for applications in the calculation of equilibriums in chemical systems. In October 1873, Horstmann announced the condition for chemical equilibrium to be that of maximum entropy. [7]

In December of 1873, independent of Horstmann, American mathematical physicist Willard Gibbs, in a footnote, stated that the condition for thermodynamic equilibrium in a chemical system at constant temperature and pressure is that a certain function, now universally known as the thermodynamic potential, should be a minimum. [8] Gibbs, however, would go on to present a more complete and rigorous treatise on the subject of equilibriums. Specifically, the two central founders of chemical thermodynamics are generally considered to be Gibbs, with the publication of his 1876 On the Equilibrium of Heterogeneous Substances, and German physician and physicist Hermann von Helmholtz (a mentor to Horstmann), with the publication of his 1882 Die Thermodynamik Chemischer Vorgänge (The Thermodynamics of Chemical Operations). [2]

In 1913, English chemist James Partington published his Text-book of Thermodynamics with Special Reference to Chemistry, followed by his 1924 updated second edition titled Chemical Thermodynamics. [6]

The founders of "modern" chemical thermodynamics are American physical chemists Gilbert Lewis and Merle Randall, for the publication of their 1923 Thermodynamics and the Free Energy of Chemical Substances, in which they were the first to apply the principles of Gibbs specifically to chemical processes, and English physical chemist Edward Guggenheim, for his 1933 Modern Thermodynamics by the Methods of Willard Gibbs. Together, the three of them unified the science of chemical thermodynamics into a coherent whole. [3]

References
1. Rossini, Frederick D. (1950). Chemical Thermodynamics, New York: John Wiley & Sons, Inc.
2. (a) Helmholtz, Hermann von. (1882). “Die Thermodynamik Chemischer Vorgänge (The Thermodynamics of Chemical Operations”, SB: 22-39, in Wissenschaftliche Abhandlungen von Hermann von Helmholtz. 3 vols. Leipzig: J.A. barth, 1882-95. 2:958-78.
(b) Cahan, David. (1993). Hermann von Helmholtz and the Foundations of Nineteenth-Century Science, (ch. 10: "Between Physics and Chemistry - Helmholtz's Route to a Theory of Chemical Thermodynamics", pg. 403-31). Berkeley: University of California Press.
3. Boerio-Goates, Juliana, and Ott, J., Bevan. (2000). Chemical Thermodynamics - Principles and Applications, (pg. 1-2). New York: Elsevier Academic Press.
4. Balzhiser, Richard, E., Samuels, Michael R., and Eliassen, John, D. (1972). Chemical Thermodynamics - the Study of Energy, Entropy, and Equilibrium. Englewood Cliffs, New Jersey: Prentice-Hall, Inc.
5. Smith, Brian E. (2005). Basic Chemical Thermodynamics. Imperial College Press.
6. Partington, J.R. (1924). Chemical Thermodynamics: An Introduction to General Thermodynamics and its Applications to Chemistry. D. Van Nostrand.
7. Horstmann, August F. (1973). “Theorie der Dissociation”, Liebig’s Annalen der Chemie und Pharmacie, Bd. 170 (CLXX), 192-210.
8. (a) Gibbs, Willard. (1873). Trans. Connect. Acad., Dec., II., footnote to pg. 393.
(b) Garrison, Fielding H. (1909). “Josiah Willard Gibbs and his Relation to Modern Science”, Popular Science, pgs. 470-84.


External links
● International Conference on Chemical Thermodynamics - IACT.