Physical chemistry is the study of macroscopic, atomic, subatomic and particulate phenomena in chemical systems in terms of physics principles, practices and concepts such as movement, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics and chemical equilibrium.
Physical chemistry, in contrast to chemical physics, is predominantly (but not always) a macroscopic or supramolecular science, since most of the principles upon which it was founded are related to the massive and not just molecular / atomic structure chemical equilibrium and colloids).
Some of the relationships that physical chemistry strives to solve include the effects of:
1. Intermolecular forces acting on the physical properties of the materials (plasticity, tensile strength, surface tension in liquids).
2. Kinetics of reaction on the speed of a reaction.
3. The identity of the ions and the electrical conductivity of the materials.
4. Surface and electrochemical science of cell membranes.
5. Interaction of one body with another in terms of amounts of heat and work called thermodynamics.
6. Heat transfer between a chemical system and its environment during phase change or chemical reaction called thermochemistry
7. Study of the colligative properties of the number of species present in the solution.
8. The number of phases, the number of components and the degree of freedom (or variance) can be correlated with each other using the phase rule.
9. Reactions of electrochemical cells.
The term "physical chemistry" was coined by Mikhail Lomonosov in 1752, when he presented a lecture course entitled "A Course in True Physical Chemistry" to students at the University of Petersburg. In the preamble to these lectures gives the definition: "Physical chemistry is the science that must explain, by virtue of the provisions of physical experiments, the reason for what is happening in complex bodies through chemical operations."
Modern physical chemistry originated in the 1860s to 1880s with work in chemical thermodynamics, electrolytes in solutions, chemical kinetics and other topics. A landmark was the publication in 1876 by Josiah Willard Gibbs of his paper, On the Balance of Heterogeneous Substances. This paper presented several of the cornerstones of physical chemistry, such as Gibbs energy, chemical potentials, and Gibbs phase rule. Other milestones include the subsequent naming and accreditation of Heike Kamerlingh Onnes enthalpy and macromolecular processes.