— Entropy change
The change in a system's entropy, measuring how energy and matter disperse. ΔS > 0 means more disorder and more accessible microstates (e.g. solid → gas); ΔS < 0 means more order. Standard molar entropies are absolute quantities tabulated in J/(mol·K).
SI unit: J/(mol·K)
Used in
- Gibbs free energy
- Spontaneity predictions