Sackur-Tetrode constant (1 K, 100 kPa)
Physico-chemicalMeasured
= −1.151 707 534 96(47)
- Value
- −1.151 707 534 96
- Standard uncertainty
- 4.7 × 10−10
- Relative uncertainty
- 4.1 × 10−10 (408 parts per trillion)
- Status
- Measured
- Symbol
- Source
- CODATA 2022 via NIST · NIST entry
Use in a calculation
Plain
LaTeX
Python
# Sackur-Tetrode constant (1 K, 100 kPa), CODATA 2022 (NIST)
sackur_tetrode_constant_1_k_100_kpa = -1.15170753496 # standard uncertainty 4.7e-10
# SciPy: scipy.constants.physical_constants['Sackur-Tetrode constant (1 K, 100 kPa)']What it is
The constant term in the Sackur–Tetrode equation for the entropy of a monatomic ideal gas, evaluated for particles of mass 1 u at 1 K and 100 kPa. Real entropies follow by adding terms for the actual mass, temperature and pressure.
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).
Relative uncertainty
| CODATA | Value (uncertainty) | Relative uncertainty | Change from previous |
|---|---|---|---|
| 2022 | −1.151 707 534 96(47) | 4.1 × 10−10 | +4.7 σ of 2018 |
| 2018 | −1.151 707 537 06(45) | 3.9 × 10−10 | +0.6 σ of 2014 |
| 2014 | −1.151 7084(14) | 1.2 × 10−6 | −0.3 σ of 2010 |
| 2010 | −1.151 7078(23) | 2.0 × 10−6 | −0.7 σ of 2006 |
| 2006 | −1.151 7047(44) | 3.8 × 10−6 | +0.0 σ of 2002 |
| 2002 | −1.151 7047(44) | 3.8 × 10−6 | +0.0 σ of 1998 |
| 1998 | −1.151 7048(44) | 3.8 × 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).