List of thermodynamic properties

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Within thermodynamics, a physical property is any property that is measurable, and whose value describes a state of a physical system. 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 so-called constants, such as Kf (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 so 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 needed 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  – Green tickY
Chemical potential \mu_i kJ/mol Green tickY Particle
number N_i
Compressibility (adiabatic) \beta_S, \kappa Pa−1 Green tickY
Compressibility (isothermal) \beta_T, \kappa Pa−1 Green tickY
Cryoscopic constant[1] K_f K·kg/mol
Density \rho kg/m3 Green tickY
Ebullioscopic constant K_b
Enthalpy H J Green tickY Green tickY
    Specific enthalpy h J/kg Green tickY
Entropy S J/K Green tickY Temperature T Green tickY (entropic)
    Specific entropy s J/(kg K) Green tickY
Fugacity f N/m² Green tickY
Gibbs free energy G J Green tickY Green tickY
    Specific Gibbs free entropy g J/(kg K) Green tickY
Gibbs free entropy \Xi J/K Green tickY Green tickY (entropic)
Grand / Landau potential \Omega J Green tickY Green tickY
Heat capacity (constant pressure) C_p J/K Green tickY
    Specific heat capacity
      (constant pressure)
c_p J/(kg·K) Green tickY
Heat capacity (constant volume) C_v J/K Green tickY
    Specific heat capacity
      (constant volume)
c_v J/(kg·K) Green tickY
Helmholtz free energy A, F J Green tickY Green tickY
Helmholtz free entropy \Phi J/K Green tickY Green tickY (entropic)
Internal energy U J Green tickY Green tickY
    Specific internal energy u J/kg Green tickY
Internal pressure  \pi _T Pa Green tickY
Mass m kg Green tickY
Particle number N_i  – Green tickY Chemical
potential \mu_i
Pressure p Pa Green tickY Volume V
Temperature T K Green tickY Entropy S
Thermal conductivity k W/(m·K) Green tickY
Thermal diffusivity \alpha m²/s Green tickY
Thermal expansion (linear) \alpha_L K−1 Green tickY
Thermal expansion (area) \alpha_A K−1 Green tickY
Thermal expansion (volumetric) \alpha_V K−1 Green tickY
Vapor quality[2] \chi  – Green tickY
Volume V m3 Green tickY Pressure P
    Specific volume v m3/kg Green tickY

See also[edit]

References[edit]

  1. ^ Aylward, Gordon; Findlay, Tristan (2002), SI Chemical Data 5th ed. (5 ed.), Sweden: John Wiley & Sons, p. 202, ISBN 0-470-80044-5 
  2. ^ Cengel, Yunus A.; Boles, Michael A. (2002). Thermodynamics: an engineering approach. Boston: McGraw-Hill. p. 79. ISBN 0-07-121688-X.