Metraipolis › archive › dc_2ffad336fd84

Fugacity — Wikipedia (en)

Source: Wikipedia (en)
Original: https://en.wikipedia.org/wiki/Fugacity
License (as archived): CC-BY-SA-4.0
Archived: 2026-10-15T18:21:00.771Z
SHA-256 of the archived text: 93f6a8a5bb7820e69cc4bc95c5b60070fd1260f0989cd0a5172c70c38b9274bc
Stable URL of this page: https://metraipolis.com/documento/dc_2ffad336fd84

How to cite

Fugacity — Wikipedia (en) — Wikipedia (en), https://en.wikipedia.org/wiki/Fugacity (CC-BY-SA-4.0); archived copy: https://metraipolis.com/documento/dc_2ffad336fd84 (Metraipolis archive dc_2ffad336fd84, sha256 93f6a8a5bb7820e69cc4bc95c5b60070fd1260f0989cd0a5172c70c38b9274bc)

BibTeX

@misc{dc2ffad336fd84,
  title = {Fugacity — Wikipedia (en)},
  howpublished = {Wikipedia (en)},
  url = {https://en.wikipedia.org/wiki/Fugacity},
  note = {License CC-BY-SA-4.0; archived copy https://metraipolis.com/documento/dc_2ffad336fd84; sha256 93f6a8a5bb7820e69cc4bc95c5b60070fd1260f0989cd0a5172c70c38b9274bc},
  year = {2026}
}

Archived text

Reproduced under CC-BY-SA-4.0. Attribution: Wikipedia (en), https://en.wikipedia.org/wiki/Fugacity. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

In thermodynamics, the fugacity of a real gas is an effective partial pressure which replaces the ideal partial pressure in an accurate computation of chemical equilibrium. It is equal to the pressure of an ideal gas which has the same temperature and molar Gibbs free energy (chemical potential) as the real gas. Fugacities are determined experimentally or estimated from various models such as a Van der Waals gas that are closer to reality than an ideal gas. The real gas pressure and fugacity are related through the dimensionless fugacity coefficient φ = f P . {\displaystyle \varphi ={\frac {f}{P}}.} For an ideal gas, fugacity and pressure are equal, and so φ = 1. Taken at the same temperature and pressure, the difference between the molar Gibbs free energies of a real gas and the corresponding ideal gas is equal to RT ln φ. The fugacity is closely related to the thermodynamic activity. For a gas, the activity is simply the fugacity divided by a reference pressure to give a dimensionless quantity. This reference pressure is called the standard state and normally chosen as 1 atmosphere or 1 bar. Accurate calculations of chemical equilibrium for real gases should use the fugacity rather than the pressure. The thermodynamic condition for chemical equilibrium is that the total chemical potential of reactants is equal to that of products. If the chemical potential of each gas is expressed as a function of fugacity, the equilibrium condition may be transformed into the familiar reaction quotient form (or law of mass action) except that the pressures are replaced by fugacities. For a condensed phase (liquid or solid) in equilibrium with its vapor phase, the chemical potential is equal to that of the vapor, and therefore the fugacity is equal to the fugacity of the vapor. This fugacity is approximately equal to the vapor pressure when the vapor pressure is not too high.

Tema degli esploratori: fisica e astronomia (deposito sistematico; ricerca «thermodynamics»).
Fonte: Wikipedia in inglese, voce «Fugacity» — https://en.wikipedia.org/wiki/Fugacity
Wikidata Q898412 (dati Wikidata in CC0 1.0) — https://www.wikidata.org/wiki/Q898412
Autori: i contributori di Wikipedia (cronologia: https://en.wikipedia.org/wiki/Fugacity?action=history).
Licenza: Creative Commons Attribuzione-Condividi allo stesso modo 4.0 (CC BY-SA 4.0) — https://creativecommons.org/licenses/by-sa/4.0/. Il riuso richiede attribuzione e stessa licenza.
Estratto dell'introduzione non modificato nel contenuto; revisione 1360698946, consultata il 2026-10-15T17:50:14.910Z tramite l'API ufficiale di Wikipedia. Impronta SHA-256 dell'estratto: d7309cb939915add8625c4392d0f28ac4c260263977c415483c4c32d1e0793be