Ideal-gas equation of state
A simple gas model relates pressure, amount, volume and temperature.
Key knowledge
An ideal gas obeys pV = nRT. For real gases it is an approximation whose quality depends on density, temperature and interactions; T is absolute thermodynamic temperature.
Values and equations
pV = nRT
- p
- Absolute gas pressure Pa
- V
- Gas volume m³
- n
- Amount of gas mol
- R
- Molar gas constant J mol⁻¹ K⁻¹
- T
- Absolute thermodynamic temperature K
Conditions and scope
- Use absolute pressure and temperature in kelvins.
- The gas is described by a uniform equilibrium state; dense gases and conditions near condensation can depart substantially from the model.
Sources · 3
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
- University Physics, volume 2: Molecular Model of an Ideal GasSamuel J. Ling, Jeff Sanny and William Moebs / OpenStax, Rice UniversityTextbook chapter
- Equation of State (Ideal Gas)NASA Glenn Research CenterTeaching resource
- Kinetic Theory · Physics (2026–27 reprint)National Council of Educational Research and Training (NCERT)Textbook chapter · PDF
Evidence and review
OpenStax 2.1, ideal molecular model and gas law; NASA pV = nRT and absolute-temperature restriction.
2026-10-10 · Ideal-gas equation and approximation limits only; no numerical R or real-gas correction is introduced.
Foundational review
2026-10-10 · Fresh primary-source inspection of the complete compact record, including every statement, equation, quantity and material condition, followed by independent AI editorial review. This check does not certify all linked lessons or every passage of every cited publication.
Sources from other places
Agreement within this scope
The dilute ideal-gas equilibrium model relates absolute pressure, volume, amount and temperature by pV=nRT.
Real gases approach this model under suitable dilute conditions; it is not an exact equation for every gas.
National Council of Educational Research and Training (NCERT)
- Kinetic Theory · Physics (2026–27 reprint) IndiaEnglish
12.3 Behaviour of gases; ideal-gas equation
- Kinetic Theory · Physics (2026–27 reprint)
Entry details
Permanent link to this entry ↗- Record identity
- physics-ideal-gas
- Revision
- core.1
- Structured reference record
- Essential core · first collection · University core expansion