Molar volume of ideal gas (273.15 K, 101.325 kPa)
Physico-chemicalExact
= 22.413 969 54… × 10−3 m3 mol−1
- Value
- 22.413 969 54… × 10−3 m3 mol−1
- Standard uncertainty
- exact
- Relative uncertainty
- exact
- Status
- Exact since the 2019 SI redefinition
- Symbol
- Source
- CODATA 2022 via NIST · NIST entry
NIST prints this exact value cut to 10 digits. ConstantID recomputes it from the defining constants: 0.022 413 969 545 014 137 735 011 102 8868…
Use in a calculation
# molar volume of ideal gas (273.15 K, 101.325 kPa), CODATA 2022 (NIST)
molar_volume_of_ideal_gas_273_15_k_101_3 = 2.2413969545014137735011102886750555e-2 # m^3 mol^-1, exact
# SciPy: scipy.constants.physical_constants['molar volume of ideal gas (273.15 K, 101.325 kPa)']What it is
The volume one mole of an ideal gas occupies at 0 °C and one standard atmosphere, about 22.4 litres, the number chemistry students learn. Real gases come close at these conditions.
It is built only from constants that have exact values since 20 May 2019, so it is exact too; CODATA 2018 was the first adjustment to list it that way.
Equations
- definition
How the value changed, 1998–2022
Each point is one CODATA adjustment, plotted as its difference from the 2022 value; the bars show one standard uncertainty (an arrowhead means the bar runs off the chart). Diamonds mark adjustments in which the value was exact.
Relative uncertainty
| CODATA | Value (uncertainty) | Relative uncertainty | Change from previous |
|---|---|---|---|
| 2022 | 22.413 969 54… × 10−3 | exact | exact |
| 2018 | 22.413 969 54… × 10−3 | exact | +0.6 σ of 2014 |
| 2014 | 22.413 962(13) × 10−3 | 5.8 × 10−7 | −0.3 σ of 2010 |
| 2010 | 22.413 968(20) × 10−3 | 8.9 × 10−7 | −0.7 σ of 2006 |
| 2006 | 22.413 996(39) × 10−3 | 1.7 × 10−6 | +0.0 σ of 2002 |
| 2002 | 22.413 996(39) × 10−3 | 1.7 × 10−6 | +0.0 σ of 1998 |
| 1998 | 22.413 996(39) × 10−3 | 1.7 × 10−6 |
“Change from previous” is the shift in the value divided by the standard uncertainty of the previous adjustment. Earlier values are converted into the current unit where NIST changed it (for example J s to J Hz⁻¹).