Toward Improved Understanding of the Physical Meaning of Entropy in Classical Thermodynamics
نویسنده
چکیده
The year 2015 marked the 150th anniversary of “entropy” as a concept in classical thermodynamics. Despite its central role in the mathematical formulation of the Second Law and most of classical thermodynamics, its physical meaning continues to be elusive and confusing. This is especially true when we seek a reconstruction of the classical thermodynamics of a system from the statistical behavior of its constituent microscopic particles or vice versa. This paper sketches the classical definition by Clausius and offers a modified mathematical definition that is intended to improve its conceptual meaning. In the modified version, the differential of specific entropy appears as a non-dimensional energy term that captures the invigoration or reduction of microscopic motion upon addition or withdrawal of heat from the system. It is also argued that heat transfer is a better model process to illustrate entropy; the canonical heat engines and refrigerators often used to illustrate this concept are not very relevant to new areas of thermodynamics (e.g., thermodynamics of biological systems). It is emphasized that entropy changes, as invoked in the Second Law, are necessarily related to the non-equilibrium interactions of two or more systems that might have initially been in thermal equilibrium but at different temperatures. The overall direction of entropy increase indicates the direction of naturally occurring heat transfer processes in an isolated system that consists of internally interacting (non-isolated) sub systems. We discuss the implication of the proposed modification on statements of the Second Law, interpretation of entropy in statistical thermodynamics, and the Third Law.
منابع مشابه
Analysis of the Characteristics, Physical Concepts and Entropy Generation in a Turbulent Channel Flow Using Vortex Blob Method
In this paper, using vortex blob method (VBM), turbulent flow in a channel is studied and physical concepts of turbulence are obtained and discussed. At first, time-averaged velocities, and , and then their fluctuations are calculated. To clarify turbulence structures, velocity fluctuations and are plotted. It is observed that turbulence structures occupy different positions and move with con...
متن کاملThe Meaning of Temperature and Entropy in Classical Statistical Mechanics
This paper began life as a serious attempt to understand the classical foundations of thermodynamics, but ended up doing crazy things like defining the temperature and entropy of single molecules. Nevertheless, there is method behind the madness, because in terms of these generalized definitions I am able to prove that the generalized notion of temperature reduces to the standard notion under c...
متن کاملConductometric Study of the Thermodynamics of Micellization of Sodium dodecylsulfate (SDS) in the Presence of Some Aromatic Ammonium Salts
The effect of three organic aromatic salts - Phenyltrimethylammonium (PhTMAB), benzyltrimethylammonium (BzTMAB) and benzyltrimethylammonium (BzTEAB) bromides - on the micellization of sodium dodecylsulfate has been investigated by conductometric method. The critical micelle concentration (CMC) values were found to decrease with increase in the concentration of the aromatic ammonium salts. Therm...
متن کاملThermodynamics and Kinetics of Spiro-Heterocycle Formation Mechanism: Computational Study
Reaction mechanism among indoline-2,3-dione, pyrrolidine-2-carboxylic acid and (Z)-2-(1-(2-hydroxynaphthalen-1-yl)ethylidene)hydroxycarboxamide to form 1’-((((aminooxy)carbonyl)amino)methyl)-2’-(1-hydroxynaphthalen-2-yl)-2’-methyl-1’,2’,5’,6’,7’,7a’-hexahydrospiro[indoline-3,3’-pyrrolo[1,2-a]imidazole-2-one was investigated using density functional theory (DFT) at B3LYP basis theory. The three-...
متن کاملPotentiometric Determination of Acidity Constants of Some Synthesized Organic Compounds in Organic-Water Media
The acidity constants of some synthesized protonated pyrazolo quinazoline compounds were determined potentiometrically at ionic strength of 0.1 M in DMF: water (60:40 v/v) system at different temperatures (298.15 K to 318.15 K). The pKa values have been found to increase with increasing electron-donating nature of substitutions. Some thermodynamics parameters such as enthalpy (ΔH°), Gibb’s free...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Entropy
دوره 18 شماره
صفحات -
تاریخ انتشار 2016