On this page you will find short articles that I will write on thermodynamics. In the three previous articles on Entropy, the definition of entropy was made, its engineering applications were briefly discussed and its microscopic meaning was tried to be explained. In this last article on entropy , interpretations of entropy outside the engineering applications will be considered. Entropy is a property or concept related to physics and thermodynamics.
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On this page you will find short articles that I will write on thermodynamics. Bu denklemde S entropiyi, kB , Boltzman sabitini 1. In this third article on entropy, the meaning of entropy at microscopic level will be examined. When mechanical engineers solve thermodynamic problems they use the macroscopic approach. In other words they define properties that can be observed or measured, summarizing the behaviour of molecules and atoms, rather than calculate the statistical behaviour of these atoms and molecules.
No doubt, this approach is much more simpler mathematically and is sufficiently accurate for solving the engineering problems. It is known from very early ages that all matter is made up of atoms and molecules. These atoms and molecules are in different forms and levels of motion.
In fact the properties that are defined at macroscopic level in thermodynamics, such as temperature, pressure, internal energy and entropy can be explained by the behaviour of atoms and molecules that form the system. A macroscopic property such as internal energy, for example, reflects the linear motion, vibrational, rotational energies of atoms and also the energy related to breaking and forming of bonds between similar molecules phase change, latent energy.
It should be mentioned that properties observed at macro level are defined for an equilibrium state. Entropy defined at macroscopic level may be computed from a reference point by using thermodynamic relations. Values of entropy given in tables are calculated in this manner. C Reynolds. In this equation, S represents entropy, kB shows the Boltzman constant 1. It should be noted that configuration is defined both space wise and energy wise.
The simple looking equation given above forms the basis of statistical thermodynamics. For those who want to read further in this topic may refer to the following books :. In order to gain a numerical insight on the topic an example is given below.
The entropy of 1 mole of carbon dioxide at 25 C temperature and kPa presure in a closed vessel is The number of molecules in the vessel is the Avagadro number, 6. If one considers the number of molecules and the rapid change of configurations, it may be understood why entropy is associated with disorder.
Another interesting note is that the product of the Boltzman and Avagadro constants is the universal gas constant. April 18,
Termodinamiğin ikinci yasası
On this page you will find short articles that I will write on thermodynamics. Bu denklemde S entropiyi, kB , Boltzman sabitini 1. In this third article on entropy, the meaning of entropy at microscopic level will be examined. When mechanical engineers solve thermodynamic problems they use the macroscopic approach.
Entropi Nedir? Örnek Hesaplamalar