Table of thermodynamic equations - Alchetron, the free social encyclopedia

This article is a summary of common equations and quantities in thermodynamics (see thermodynamic equations for more elaboration). SI units are used for absolute temperature, not Celsius or Fahrenheit.

Definitions

Many of the definitions below are also used in the thermodynamics of chemical reactions.

Equations

The equations in this article are classified by subject.

Entropy

S = k B ( ln ⁡ Ω ) , where k_B is the Boltzmann constant, and Ω denotes the volume of macrostate in the phase space or otherwise called thermodynamic probability.

d S = δ Q T , for reversible processes only

Statistical physics

Below are useful results from the Maxwell–Boltzmann distribution for an ideal gas, and the implications of the Entropy quantity. The distribution is valid for atoms or molecules constituting ideal gases.

Corollaries of the non-relativistic Maxwell–Boltzmann distribution are below.

Quasi-static and reversible processes

For quasi-static and reversible processes, the first law of thermodynamics is:

d U = δ Q − δ W

where δQ is the heat supplied to the system and δW is the work done by the system.

Thermodynamic potentials

The following energies are called the thermodynamic potentials,

and the corresponding fundamental thermodynamic relations or "master equations" are:

Maxwell's relations

The four most common Maxwell's relations are:

More relations include the following.

Other differential equations are:

Quantum properties

U = N k B T 2 ( ∂ ln ⁡ Z ∂ T ) V

S = U T + N ∗ S = U T + N k B ln ⁡ Z − N k ln ⁡ N + N k Indistinguishable Particles

where N is number of particles, h is Planck's constant, I is moment of inertia, and Z is the partition function, in various forms:

References

Table of thermodynamic equations Wikipedia

(Text) CC BY-SA

Contents