# What is Classical thermodynamics: Definition and 16 Discussions

Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, radiation, and physical properties of matter. The behavior of these quantities is governed by the four laws of thermodynamics which convey a quantitative description using measurable macroscopic physical quantities, but may be explained in terms of microscopic constituents by statistical mechanics. Thermodynamics applies to a wide variety of topics in science and engineering, especially physical chemistry, biochemistry, chemical engineering and mechanical engineering, but also in other complex fields such as meteorology.
Historically, thermodynamics developed out of a desire to increase the efficiency of early steam engines, particularly through the work of French physicist Nicolas Léonard Sadi Carnot (1824) who believed that engine efficiency was the key that could help France win the Napoleonic Wars. Scots-Irish physicist Lord Kelvin was the first to formulate a concise definition of thermodynamics in 1854 which stated, "Thermo-dynamics is the subject of the relation of heat to forces acting between contiguous parts of bodies, and the relation of heat to electrical agency."
The initial application of thermodynamics to mechanical heat engines was quickly extended to the study of chemical compounds and chemical reactions. Chemical thermodynamics studies the nature of the role of entropy in the process of chemical reactions and has provided the bulk of expansion and knowledge of the field. Other formulations of thermodynamics emerged. Statistical thermodynamics, or statistical mechanics, concerns itself with statistical predictions of the collective motion of particles from their microscopic behavior. In 1909, Constantin Carathéodory presented a purely mathematical approach in an axiomatic formulation, a description often referred to as geometrical thermodynamics.

View More On Wikipedia.org
1. ### A What is the heat capacity of water in meta-stable equilibrium?

Dear experts, I noticed that super-heated water (liquid water with temperature above 100*C) undergoes boiling when pushed outside the meta-stable equilibrium. I was wondering, is the heat capacity of liquid water above 100*C the same as liquid water with temperature between 0*C and 100*C...
2. ### I Reversible / Irreversible Fundamental Equation

As far as I learned, the following statements should be correct (for closed systems, no chemical reactions), irrespective whether the process is reversible or irreversible (since S and V are state variables): dU=TdS−pdV dU=dQ+dW Does this imply, that the statement: dU≤TdS−pdV is wrong? This...
3. ### A Thermodynamics Derivative Reduction Problems

Hi everyone, I'm in a graduate level mechanical engineering thermodynamics class. We're working on derivative reductions using the gibbs and maxwell relations. I was wondering if anyone has any good sources of practice problems that I could use. I've looked through my textbook and there are...
4. ### Derive ##\dfrac{\rho_1}{\rho_2}=\dfrac{T_2}{T_1}##

I just found here(https://byjus.com/physics/relation-between-density-and-temperature/#:~:text=Density and Temperature Relationship 1 When density increases,,reduces. 4 When the temperature decrease, density increases.) that P=##rho##RT. So they just took ##\rho=\frac{n}{V}##...
5. ### I Book suggestions for classical thermodynamics

I was looking for book on classical thermodynamics. I found lot of related posts in PSE but couldn't find a book which type I was expecting. I was searching for book which covers the whole thermodynamics (not QM but it's ok if there's some knowledge of Relativity), and I want some problems in...
6. ### Assumed value of pressure during quasistatic compression

My text (Ian Ford - Statistical physics) describes an ideal gas system in a piston being quasistatically compressed by a piston head of area A under external force f. It assumes the system has a uniform pressure p. All good so far. Then it says: "the force pA equals the applied external force f"...
7. ### Classical Recommendation for a classical thermodynamics book

Hello! I am a high school student and I would need some guidance regarding a thermodynamics book. I am reading and solving through these three: 1.Resnick,Halliday and Walker 2.University Physics- Young and Freedman 3.An introduction to mechanics-Kleppner and Kolenkow(purely for mechanics) Based...
8. ### How is internal energy U(S,V) a function of temperature?

In my chemical thermodynamics class/notes (and other references I've used) it is stated throughout that internal energy U is a function of entropy and volume , i.e. it's "natural" variables are S and V: U = U(S,V) I suspect that I must take this "axiomatically" and move on. Since U is a state...
9. ### Engineering Good Resources to learn Classical Thermodynamics

Hi, I'm currently taking thermodynamics in second year mechanical engineering. I read previous threads on here about good textbooks, and everyone seemed to agree that Cengel's book is really good. Its the book we use in class, but at times I don't think it explains everything as fully as it...
10. ### Classical thermodynamics problem

Homework Statement (i) State the Second Law of Thermodynamics in one or other of its forms. (ii) The heat capacity per unit volume of a particular solid at low temperatures is equal to CT3; find expressions for its internal energy and entropy S per unit volume (ignoring the effects of...
11. ### Classical Thermodynamics for Statistical Mechanics

Hi all, It's my first time to ask a question here I am now taking a Thermodynamics course and I have the authority to choose what topics to study in this course. My intention is to be able to study statistical mechanics afterward. So I need thermodynamics that will be useful when studying...
12. ### Constructivist Philosophy and Classical Thermodynamics

Can anyone tell me how a constructivist philosopher would view concepts in classical thermodynamics, say like the state variables pressure, temperature, internal energy, and entopy? I read in Wikipedia that "Constructivists maintain that scientific knowledge is constructed by scientists and...
13. ### Classical thermodynamics Q's.

Classical thermodynamics Q's. Hello ! I have some conceptual problems that are confusing me, hope someone could help. Book Being used: Fundamentals of Engineering Thermodynamics. (Micheal J. Moran & Howard N. Shapiro). 1) Analytical Kelvin-Planck statement. (pg. 224) Wcycle <= 0. (...
14. ### Imperfections of classical thermodynamics

Here is simple counter example to 2nd law of thermodynamics - converting heat into work. Everything is in vacuum, without gravity: Take a tube with interior covered with mirror. Fix two transparent separators inside and place hot gas between them. Now place two mirrors on both sides, which...
15. ### Prof teaches Statistical thermodynamics in a Classical Thermodynamics class

I'm just finishing up a "Classical Thermodynamics" class. Here is a list of topics we covered: Chapter 1: Ideal gas, equipartition of energy, heat and work, heat capacities, rates of processes Chapter 2: Multiplicity of an Einstein solid, of an ideal gas, of interacting systems Chapter 3...
16. ### Classical thermodynamics problem.

Hm, I'm pretty much stuck on a thermodynamics problem. If you consider two identical masses of water at temperatures T1 and T2, what is the global increase in entropy after they have reached thermal equilibrium. The best I could come up with is [del]S = m*C*ln(T2/T1). The answer listed...