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Definition, concept, meaning, what is physical chemistry
1. Concept of physical chemistryPhysical chemistry is a scientific discipline whose aim is the study of chemical processes from a physical point of view. Physical chemistry gathers the data necessary for the definition of the properties and characteristics of gases, liquids, solids, solutions and dispersions of colloidal in order to systematize them and give them a theoretical basis. Also establishes the relations of power in the physical changes and tries to predict in that magnitude and speed are produced. To realize this purpose physical chemistry uses microscopic and macroscopic approaches, establishing laws, models and assumptions that allow to explain and predict phenomena studied, in fact, this science is a field where the math and physics are widely applied in the study and resolution of problems related to chemical processes of interest. But, in addition, it supports widely in experimentation, whose techniques and methods play a so decisive role as laws and mathematical methods.
For a chemical engineer is very important to understand the chemical nature of the system that is trying to, being able to predict how a chemical reaction will be developed, and especially with that speed, in order to transfer operation of the laboratory to a commercial-scale plant. This course provides a general basis of main laws and models that govern physical and chemical changes of matter of the seventh semester of chemical engineering students, and gives you the tools to study subjects like engineering the reactions and unit operations II and III. To meet this objective, this course explores the fundamentals of phases equilibria, the chemical kinetics, Catalysis of reactions and properties of solutions electrolytic and non-electrolytic.
2. Definition of physical chemistryPhysical chemistry is a field of study so general that it can be compared to all that which reacts, has life and manifests as a sustainable development in nature, as the physics and chemistry is a study that is done all what works through interactions of chemistry with the movement and everything is physical. Physical chemistry is a branch of chemistry, as it represents all the application of chemistry to natural phenomena of the Earth. Physical chemistry study thermodynamics, electrochemistry and quantum mechanics from a very Atomic point of view.
Physical chemistry is born from the interest of studying the different systems of electric reaction manifested in compounds chemical, from this different techniques have been developed to use chemical compounds studied in laboratories for fuels, fossil often design. Electrochemistry and Thermochemistry, as major fields of study in the physics and chemistry since as mentioned above, led to the development of fuels and media for the use of machines that would allow for the evolution of mankind, this is a topic very important when making a reference of the industrial revolution and its impact on society. The most notable physical chemistry studies were Alessandro Volta, who is owed the development of different works in pro of conduction of electricity, inclusive, Volt unit reached that name in honor to him.
Michael Faraday also you to much work for the contribution of the physics and chemistry because the statement the first laws of electrolysis, which dictate the following: 1. the mass of a substance altered at an electrode during electrolysis is directly proportional to the quantity of electricity transferred to this electrode. The quantity of electricity refers to the quantity of electric charge, which is generally measured in coulombs. 2. For a certain amount of electricity (electric charge), the mass of an elemental material altered at an electrode is directly proportional to the equivalent weight of the element. The equivalent weight of a substance is its molar mass divided by an integer that depends on the reaction that takes place in the material.
3. Meaning of physical chemistryPhysical chemistry, also called physical chemistry is a subdiscipline of chemistry that studies the matter using physical and chemical concepts.
According to the renowned American chemist Gilbert Lewis, "physical chemistry is anything interesting", which probably referred to the fact that many phenomena of nature regarding the matter are of main interest in physical chemistry.
Physical chemistry is a branch where takes place a change of different Sciences, such as chemistry, physics, thermodynamics, electrochemistry and quantum mechanics functions where mathematics can represent interpretations at the molecular and atomic level structural. Changes in temperature, pressure, volume, heat and work systems, solid, liquid or gaseous are also related to these interpretations of molecular interactions.
The American physicist of the century XIX Willard Gibbs is also considered the founding father of physical chemistry, where in 1876 publication called On the Equilibrium of Heterogeneous Substances (study on the equilibrium of heterogeneous substances) coined terms such as free energy, chemical potential, and rule of phases, who years later would be of main interest of study in this discipline.
The modern physics and chemistry have firm foundations in pure physics. Important areas of study therein include (thermodynamic chemistry) Thermochemistry, Kinetics and quantum chemistry, chemical dynamics, statistical mechanics, electrochemistry, magnetochemistry, energy, chemical and solid-state surfaces, and spectroscopy. Physical chemistry is a fundamental part in the study of materials science.
History of physical chemistryPhysical chemistry was not constituted as independent of chemistry specialty until the beginning of the 20th century. Dates of creation of two of the first magazines that incorporated this name to your title can be taken as a starting point for the new specialty: the German Zeitschrift für Chemie physicalische directed by Wolfgang Ostwald (1853-1932) and Jacobus Henricus Van't Hoff (1850-1930), which began publication in 1887, and the American Journal of Physical Chemistry, directed by Wilder Dwight Bancroft (1867-1953) since 1896. Despite this, during the 19th century were notable contributions to some of the fields that usually tend to gather under the physics and chemistry, such as electrochemistry, Thermochemistry or chemical kinetics.
The work of Alessandro Volta (1745-1827), especially the battery that bears his name, was the starting point of many works in which we studied the effects of electricity on chemical compounds. At the beginning of the 19th century, Humphry Davy (1778-1829) did pass through soda and potash melted, which allowed him to study two new metals: sodium and potassium. His main disciple and his successor at the Royal Institution was Michael Faraday (1791-1867), who continued the investigations of his master. In an article published in 1834, Faraday proposed its two known laws of electrolysis. The first says that the amount of substance that is deposited onto an electrode is proportional to the quantity of electric charge flowing through the circuit. In its second Act, Faraday says that the amount of electric charge that causes detachment of one gram of hydrogen produces the detachment of an amount equal to the electrochemical equivalent of other substances.
The work carried out by Antoine Lavoisier (1743-1794) and Pierre-Simon Laplace (1749-1827) are usually considered the starting point of the Thermochemistry. They designed a new instrument, the calorimeter, which could perform measurements on the amount of "caloric" released during chemical reactions. Laplace and Lavoisier thought that the heat was one of the imponderable elements and gases were compounds of caloric and the corresponding element. In the first half of the 19th century, the idea of the calorie was abandoned and began to perform research that allowed the establishment of the laws of thermodynamics. The application of this research to chemical processes enabled the emergence of Thermochemistry, thanks to the work of authors such as Marcelin Berthelot (1827-1907) and Henry Le Chatelier (1850-1936).
One of the first work dedicated to the study of chemical kinetics was carried out by Ludwig Ferdinand Wilhelmy (1812-1864) on the rate of change of configuration of certain sugars in the presence of an acid. Mid-19th century, Wilhelmy came to the conclusion that the speed of change was proportional to the concentration of sugar and acid and that also varied with temperature. The collaboration between a chemist, George Vernon Harcourt (1834-1919), and a mathematician William Esson (1838-1916), allowed the introduction of differential equations in the study of chemical kinetics. Esson was the introducer of the concepts of reactions of "first order", whose speed is proportional to the concentration of a single reagent, and reactions of "second order", in which the speed is proportional to the product of two concentrations. In the last years of the 19th century, the works of Jacobus Henricus Van't Hoff (1852-1911) had a great influence in this and other fields of chemistry. His contributions include the introduction of the "differential method" for the study of chemical reaction speed and his famous equation that allows to relate the speed and temperature of the reaction.
The development of quantum mechanics and its application to the study of chemical phenomena has been one of the most notable changes that have occurred in 20th century chemistry. Scientists have made more contributions in this sense include Linus Pauling, author of books as significant as his Introduction to Quantum Mechanics, With applications to Chemistry (1935) or The Nature of the Chemical Bond and the Structure of Molecules and Crystals (1939). Among many other contributions, Linus Pauling was the introducer of our modern concept of electronegativity.