Sackur–Tetrode Constant

The absolute entropy of one mole of ideal monatomic gas at standard conditions.

Specifications & Metrics

symbol

S0/R

status

Measured — CODATA 2022 adjustment

value

-1.15170753496 ± 4.7 × 10⁻¹⁰

Core Principles & Analysis

• About −1.151 7 in units of R, the first absolute entropy ever computed.
• Solves the Gibbs paradox by counting indistinguishable particles correctly.
• Derives the entropy of noble gases from first principles, with no fitted parameters.