In many labs and industrial settings, choosing the right gas and condition streamlines experiments and equipment design. A quick, practical list of gases and their typical behavior helps you decide whether an ideal-gas assumption is acceptable or if corrections are needed.
There are 12 Examples of Ideal Gases, ranging from Argon (Ar) to Xenon (Xe). For each entry, data are organized under Typical temp (°C), Typical pressure (atm), Z (typical) to show representative conditions and a compressibility factor for corrections — you’ll find below.
How close do gases like Argon (Ar) and Xenon (Xe) behave like ideal gases at normal lab conditions?
At moderate temperatures and near 1 atm most noble gases behave close to ideal, with Z values near 1; lighter ones (Argon) are typically nearer ideal than heavier ones (Xenon), which show slightly larger deviations, so check the Z (typical) column before assuming ideality.
How should I use the Typical temp (°C), Typical pressure (atm), Z (typical) columns in calculations?
Convert temperatures to Kelvin and use PV = Z n R T when Z differs from 1; the Typical columns give a starting point for choosing conditions, and you can interpolate Z for intermediate states or apply empirical corrections if working at high pressure or very low temperature.
Examples of Ideal Gases
| Name | Typical temp (°C) | Typical pressure (atm) | Z (typical) |
|---|---|---|---|
| Helium (He) | -50–200°C | 0.01–10 atm | 0.999–1.002 |
| Neon (Ne) | -150–150°C | 0.01–10 atm | 0.999–1.003 |
| Argon (Ar) | -100–150°C | 0.01–10 atm | 0.998–1.005 |
| Krypton (Kr) | -50–150°C | 0.01–10 atm | 0.996–1.004 |
| Xenon (Xe) | -20–100°C | 0.01–5 atm | 0.995–1.003 |
| Hydrogen (H2) | -100–150°C | 0.01–10 atm | 0.998–1.003 |
| Nitrogen (N2) | -50–150°C | 0.01–10 atm | 0.999–1.002 |
| Oxygen (O2) | -50–150°C | 0.01–10 atm | 0.998–1.003 |
| Carbon monoxide (CO) | -50–150°C | 0.01–10 atm | 0.999–1.002 |
| Methane (CH4) | -50–150°C | 0.01–10 atm | 0.998–1.002 |
| Nitric oxide (NO) | -50–150°C | 0.01–5 atm | 0.995–1.005 |
| Carbon dioxide (CO2) | 40–200°C | 0.01–5 atm | 0.990–1.010 |
Images and Descriptions
Helium (He)
Light, inert noble gas with very low polarizability so intermolecular forces are negligible; behaves almost perfectly ideal across wide lab temperatures and moderate pressures. Used in cryogenics, balloons, leak detection and as a protective gas.
Neon (Ne)
Noble gas with low intermolecular attraction; near-ideal at common lab and room temperatures and low-to-moderate pressures. Familiar from neon lighting and vacuum tubes; chemically inert and simple to model.
Argon (Ar)
Abundant noble gas in air that shows very small deviations from ideality at typical temperatures and pressures. Widely used as an inert shielding gas in welding and in laboratory atmospheres.
Krypton (Kr)
Heavier noble gas with modest polarizability but still near-ideal under practical lab/engineering conditions at moderate pressures. Commonly used in lighting, lasers and certain detectors.
Xenon (Xe)
Dense noble gas that remains close to ideal at room temperature and low-to-moderate pressures; larger atoms show slightly larger deviations but still within ±2%. Used in flash lamps, ion propulsion and medical imaging.
Hydrogen (H2)
Smallest molecule with weak intermolecular forces; behaves nearly ideally over wide temperature ranges at modest pressures. Important fuel, industrial reactant, and carrier gas in analytical chemistry.
Nitrogen (N2)
Major component of air that closely follows the ideal gas law at typical ambient temperatures and pressures. Widely used in industry for inert atmospheres, blanks, and cryogenics.
Oxygen (O2)
Diatomic gas that is close to ideal at normal temperatures and pressures away from condensation. Commonly used medically and industrially; care required near liquefaction where non-ideal effects grow.
Carbon monoxide (CO)
Small, nonpolar-like molecule (polar bond but low overall interaction) that behaves nearly ideally under common lab conditions. Used in synthesis and industrial chemistry; toxic gas found in combustion processes.
Methane (CH4)
Small, nonpolar hydrocarbon and the primary component of natural gas; shows very small deviations from ideality at room temperature and moderate pressures, making it easy to model in engineering.
Nitric oxide (NO)
A small, mildly polar diatomic radical that approximates ideal behavior at ambient temperatures and low pressures. Used in biochemical signaling studies and some industrial applications; reactive so handled carefully.
Carbon dioxide (CO2)
Although CO2 is non-ideal near room-temperature saturation, at temperatures safely above its critical point (~31°C) and at low-to-moderate pressures it shows Z within ±2%. Widely used in fire suppression, beverage carbonation and industrial processes.
