Term: ideal gas
https://doi.org/10.1351/goldbook.I02935

Definition:
Gas which obeys the equation of state pV = nRT (the ideal gas law; p is the pressure, V the volume, n the amount of molecules, R the gas constant and T the thermodynamic temperature). For an ideal gas the fugacity, f, of each constituent B is equal to its partial pressure, pB, fB = pB = xB.p, where xB is the amount fraction of B.

Related Terms:
1) gas constant (http://doi.org/10.1351/goldbook.G02579).
2) thermodynamic temperature (http://doi.org/10.1351/goldbook.T06321).
3) constituent (http://doi.org/10.1351/goldbook.C01281).
4) partial pressure (http://doi.org/10.1351/goldbook.P04420).
5) fugacity (http://doi.org/10.1351/goldbook.F02543).

Source: Physical Chemistry Division, unpublished

Citation: 'ideal gas' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.I02935

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