The physicochemical phenomena are those that modify, at the same time, the internal (molecular) nature of substances, as well as their physical state, that is, their shape or the arrangement of their constituent elements. For example: solutions, catalysis, electrolysis.
Traditionally, a distinction is made between physical phenomena Y chemicals on the basis that the former modify the state of an object or substance without altering its composition, while the latter alter the very essence of the object or substance.
Thus, melting an ice cube or boiling water will be examples of physical phenomena, since the substance retains its composition (HtwoO), while the oxidation of an iron nail or the combustion of wood will be physical phenomena that transform one substance into a different one.
Physicochemical phenomena, on the other hand, carry out both tasks at the same time, so their object of study is the molecular relationships and interactions that matter presents in its various states and physical processes.
The origin of this discipline dates back to the 19th century, when the American chemist Willard Gibbs published his Study on the balance of heterogeneous substances, where he postulated terms such as free energy, chemical potential and phase rule, which today constitute some of the main points of interest in physical chemistry.
We could conclude that the area of expertise of physical chemistry are those perspectives that physics and chemistry separately fail to address or explain satisfactorily.
Examples of Physicochemical Phenomena
- solutions. Solutions are homogeneous mixtures of two or more pure substances that react with each other and are found together in varying proportions. An electrochemical link is produced between them that recomposes the atomic bonds of each one, so they cannot be separated except by means of certain physicochemical processes.
- Catalysis. This is the name given to the processes by which the speed of a certain chemical reaction is increased through the participation of another substance, foreign to the original reaction, which is called a catalyst and which, by not participating in the reaction, maintains its mass. constant.
- Transport. Transport phenomena are those that transmit a quantity of movement, energy and/or matter between substances or actors involved, and that are studied from three different levels: microscopic, macroscopic and molecular, using a joint physical-chemical perspective. -math.
- Ion exchanges. This is the process of transmission of electrically charged atoms or molecules (ions) between two electrically conductive substances (electrolytes) or one of them and a chemical complex (coordination bonds). It is also a phenomenon favored in processes of purification, separation or decontamination of ionic solutions.
- Chemical balance. This equilibrium appears when the substances involved in a reversible chemical reaction do not have a concentration favorable to either of the two directions in which the chemical change can occur (forward or reverse).
- Liquid crystal. A liquid crystal is called a very particular state of matter aggregation, which responds to both the physical considerations of the solid state and the liquid state simultaneously. They are of particular interest for the physicochemical study of the phases.
- Polymer relaxation. This is the name given to a phenomenon in which certain plastics (and hence their name) modify their shape and structure in the face of a sustained effort applied to them, arranging the polymer chains in the most energetically favorable position, that is, the that contains less entropy.
- quantum leaps. A quantum jump is the sudden and sudden change of state of matter, which occurs at atomic levels and is part of the phenomena explored through spectroscopy (quantum chemistry). It is, for example, the sudden state of excitement of an electron in an atom when it is hit with a photon (light).
- Electrolysis. Mechanism used to separate the chemical elements within a compound from the introduction of electricity, forcing the capture and release of electrons at each pole (cathode and anode respectively), thus generating reduction and oxidation processes at the same time.
- energy transfers. Physical chemistry is particularly interested in the phenomena of energy transfer, whether caloric or electrical, and therefore attends to almost all cases of energetic interaction of molecules of two or more interacting substances.