Comments on ‘‘Ideal gas and the second law of thermodynamics’’

1984 ◽  
Vol 52 (5) ◽  
pp. 462-463 ◽  
Author(s):  
Gautam Mandal
Keyword(s):  
Second Law Of Thermodynamics ◽  
Ideal Gas ◽  
Second Law

Energy and heat

2017 ◽  
Author(s):  
Andrew Clarke
Keyword(s):  
Thermal Equilibrium ◽  
Growth And Development ◽  
Constant Pressure ◽  
Open Systems ◽  
Second Law Of Thermodynamics ◽  
Ideal Gas ◽  
Second Law ◽  
Total Entropy ◽  
Isothermal Conditions ◽  
System P

Energy is the capacity to do work and heat is the spontaneous flow of energy from one body or system to another through the random movement of atoms or molecules. The entropy of a system determines how much of its internal energy is unavailable for work under isothermal conditions, and the Gibbs energy is the energy available for work under isothermal conditions and constant pressure. The Second Law of Thermodynamics states that for any reaction to proceed spontaneously the total entropy (system plus surroundings) must increase, which is why metabolic processes release heat. All organisms are thermodynamically open systems, exchanging both energy and matter with their surroundings. They can decrease their entropy in growth and development by ensuring a greater increase in the entropy of the environment. For an ideal gas in thermal equilibrium the distribution of energy across the component atoms or molecules is described by the Maxwell-Boltzmann equation. This distribution is fixed by the temperature of the system.

Classical Gases: Ideal and Otherwise

2019 ◽  
pp. 81-98
Author(s):  
Robert H. Swendsen
Keyword(s):  
Particle Number ◽  
Second Law Of Thermodynamics ◽  
Ideal Gas ◽  
Second Law ◽  
Interacting Particles ◽  
Entropy Maximum ◽  
General Systems ◽  
Two Systems ◽  
The Ideal

As preparation for the derivation of the entropy for systems with interacting particles, the position and momentum variables are treated simultaneously, in this chapter, for the ideal gas. Releasing a constraint on the exchange of volume between two systems leads to an entropy maximum, just as the release of an energy- or particle-number constraint. This same principle is shown to be true for asymmetric pistons, which allow the total volume to change. The entropy of systems with interacting particles is then derived. The Second Law of Thermodynamics is established for general systems. Finally, the Zeroth Law of Thermodynamics is derived.

The Second Law

2021 ◽  
pp. 49-84
Author(s):  
Daniel V. Schroeder
Keyword(s):  
Simple Model ◽  
Large Scale ◽  
Second Law Of Thermodynamics ◽  
Ideal Gas ◽  
The Other ◽  
Model Systems ◽  
Second Law ◽  
Magnetic Dipoles ◽  
Einstein Model ◽  
Identical Quantum

Why are so many large-scale processes irreversible, happening in one direction but not the other as time passes? This chapter answers that question using three simple model systems: a collection of two-state particles such as flipped coins or elementary magnetic dipoles; the Einstein model of a solid as a collection of identical quantum oscillators; and a monatomic ideal gas such as helium or argon. For each system we learn to calculate the multiplicity: the number of possible microscopic arrangements. Taking the logarithm of the multiplicity gives the entropy. And the laws of probability then imply the second law of thermodynamics: Entropy tends to increase.

scholarly journals On the Assumption of the Independence of Thermodynamic Properties on the Gravitational Field

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 930
Author(s):  
Corti
Keyword(s):  
Gravitational Field ◽  
Thermodynamic Properties ◽  
Internal Energy ◽  
Center Of Mass ◽  
Second Law Of Thermodynamics ◽  
Ideal Gas ◽  
Thermodynamic Efficiency ◽  
Second Law ◽  
Cyclic Process ◽  
Carnot Cycle

A reversible cyclic process is analyzed in which the center of mass of an ideal gas is raised in a gravitational field during both an expansion phase and a subsequent contraction phase, with the gas returning to its initial height in a final step. When the properties of the gas are taken as uniform, the thermodynamic efficiency of this cycle is able to exceed that of a corresponding Carnot cycle, which is a violation of the second law of thermodynamics. The source of this discrepancy was previously claimed, when analyzing a similar heating and cooling of a sphere, to be the assumed independence of the internal energy on the gravitational field. However, this violation is only apparent since all of the effects of the gravitational field were not incorporated fully into the thermodynamic analysis of the cycle. When all the influences of the gravitational field are considered, no possible violation of the second law can occur. The evaluation of the entropy changes of the gas throughout the cycle also highlights other key inconsistencies that arise when the full effects of the gravitational field are neglected. As the analysis of the cycle provided here shows, the assumption of the independence of the internal energy, as well as other thermodynamic properties, on the gravitational field strength can still be invoked.

Entropy, the magic ruler?

2021 ◽  
Vol 34 (2) ◽  
pp. 227-230
Author(s):  
David Van Den Einde
Keyword(s):  
18Th Century ◽  
Second Law Of Thermodynamics ◽  
Ideal Gas ◽  
Heat Energy ◽  
Second Law ◽  
Cyclical Process ◽  
T1 And T2 ◽  
The Ideal

The 18th century foundations of the second law of thermodynamics are discussed. The association between Carnot efficiency and Clausius entropy is described to show the questionable use of Clausius entropy as proof of Carnot’s assumption that the rate the ideal gas can convert heat energy to work between temperatures T1 and T2 sets a universal limit on the convertibility of heat to work by all 2T cyclical process.

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