ConstantID

Sackur-Tetrode constant (1 K, 101.325 kPa)

Physico-chemicalMeasured

S0/R = −1.164 870 521 49(47)

Value
−1.164 870 521 49
Standard uncertainty
4.7 × 10−10
Relative uncertainty
4.0 × 10−10 (403 parts per trillion)
Status
Measured
Symbol
S0/R
Source
CODATA 2022 via NIST · NIST entry

Use in a calculation

# Sackur-Tetrode constant (1 K, 101.325 kPa), CODATA 2022 (NIST)
sackur_tetrode_constant_1_k_101_325_kpa = -1.16487052149  # standard uncertainty 4.7e-10

# SciPy: scipy.constants.physical_constants['Sackur-Tetrode constant (1 K, 101.325 kPa)']

What it is

The constant term in the Sackur–Tetrode equation for the entropy of a monatomic ideal gas, for particles of mass 1 u at 1 K and one standard atmosphere.

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).

Sackur-Tetrode constant (1 K, 101.325 kPa): CODATA values 1998–2022 relative to the 2022 value, in parts per million, with one-standard-uncertainty bars−4−20+2+4parts per million1998200220062010201420182022

Relative uncertainty

Sackur-Tetrode constant (1 K, 101.325 kPa): relative standard uncertainty in each CODATA adjustment, logarithmic scale10⁻¹⁰10⁻⁹10⁻⁸10⁻⁷10⁻⁶10⁻⁵1998200220062010201420182022
CODATAValue (uncertainty)Relative uncertaintyChange from previous
2022−1.164 870 521 49(47)4.0 × 10−10 +4.6 σ of 2018
2018−1.164 870 523 58(45)3.9 × 10−10 +0.6 σ of 2014
2014−1.164 8714(14)1.2 × 10−6 −0.3 σ of 2010
2010−1.164 8708(23)2.0 × 10−6 −0.7 σ of 2006
2006−1.164 8677(44)3.8 × 10−6 +0.0 σ of 2002
2002−1.164 8677(44)3.8 × 10−6 +0.0 σ of 1998
1998−1.164 8678(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).