# List of thermodynamic properties

In thermodynamics, a physical property is any property that is measurable, and whose value describes a state of a physical system. Thermodynamic properties are defined as characteristic features of a system, capable of specifying the system's state. Some constants, such as the ideal gas constant, R, do not describe the state of a system, and so are not properties. On the other hand, some constants, such as K$_f$ (the freezing point depression constant, or cryoscopic constant), depend on the identity of a substance, and so may be considered to describe the state of a system, and therefore may be considered physical properties.
"Specific" properties are expressed on a per mass basis. If the units were changed from per mass to, for example, per mole, the property would remain as it was (i.e., intensive or extensive).

## Regarding work and heat

Work and heat are not thermodynamic properties, but rather process quantities: flows of energy across a system boundary. Systems do not contain work, but can perform work, and likewise, in formal thermodynamics, systems do not contain heat, but can transfer heat. Informally, however, a difference in the energy of a system that occurs solely because of a difference in its temperature is commonly called heat, and the energy that flows across a boundary as a result of a temperature difference is "heat".
Altitude (or elevation) is usually not a thermodynamic property. Altitude can help specify the location of a system, but that does not describe the state of the system. An exception would be if the effect of gravity need to be considered in order to describe a state, in which case altitude could indeed be a thermodynamic property.
Thermodynamic properties and their characteristics :
| Property | Symbol | Units | Extensive? | Intensive? | Conjugate | Potential? |
| Activity | a | – | | Y | | |
| Chemical potential | μ$_i$ | kJ/mol | | Y | Particle number N$_i$ | |
| Compressibility (adiabatic) | β$_S$, κ | Pa$^{−1}$ | | Y | | |
| Compressibility (isothermal) | β$_T$, κ | Pa$^{−1}$ | | Y | | |
| Cryoscopic constant | K$_f$ | K·kg/mol | | Y | | |
| Density | ρ | kg/m$^3$ | | Y | | |
| Ebullioscopic constant | K$_b$ | K·kg/mol | | Y | | |
| Enthalpy | H | J | Y | | | Y |
| Specific enthalpy | h | J/kg | | Y | | |
| Entropy | S | J/K | Y | | Temperature T | Y (entropic) |
| Specific entropy | s | J/(kg K) | | Y | | |
| Fugacity | f | N/m$^2$ | | Y | | |
| Gibbs free energy | G | J | Y | | | Y |
| Specific Gibbs free energy | g | J/kg | | Y | | |
| Gibbs free entropy | Ξ | J/K | Y | | | Y (entropic) |
| Grand / Landau potential | Ω | J | Y | | | Y |
| Heat capacity (constant pressure) | C$_p$ | J/K | Y | | | |
| Specific heat capacity (constant pressure) | c$_p$ | J/(kg·K) | | Y | | |
| Heat capacity (constant volume) | C$_v$ | J/K | Y | | | |
| Specific heat capacity (constant volume) | c$_v$ | J/(kg·K) | | Y | | |
| Helmholtz free energy | A, F | J | Y | | | Y |
| Helmholtz free entropy | Φ | J/K | Y | | | Y (entropic) |
| Internal energy | U | J | Y | | | Y |
| Specific internal energy | u | J/kg | | Y | | |
| Internal pressure | π$_T$ | Pa | | Y | | |
| Mass | m | kg | Y | | | |
| Particle number | N$_i$ | – | Y | | Chemical potential μ$_i$ | |
| Pressure | p | Pa | | Y | Volume V | |
| Temperature | T | K | | Y | Entropy S | |
| Thermal conductivity | k | W/(m·K) | | Y | | |
| Thermal diffusivity | α | m$^2$/s | | Y | | |
| Thermal expansion (linear) | α$_L$ | K$^{−1}$ | | Y | | |
| Thermal expansion (area) | α$_A$ | K$^{−1}$ | | Y | | |
| Thermal expansion (volumetric) | α$_V$ | K$^{−1}$ | | Y | | |
| Vapor quality | χ | – | | Y | | |
| Volume | V | m$^3$ | Y | | Pressure P | |
| Specific volume | ν | m$^3$/kg | | Y | | |