kJ/(mol·K)
kilojoule per mole kelvin
Molar entropyexact by definition
The kilojoule per mole per kelvin is a thousand joules per mole per kelvin, an exact decimal prefix. It is uncommon for entropies, which are naturally sized in J/(mol·K), but it appears where entropy terms are combined with enthalpies already expressed in kJ/mol, since TΔS must be in the same units as ΔH before they can be subtracted.
Watch out: The classic Gibbs free energy error is exactly this mismatch: ΔH in kJ/mol and ΔS in J/(mol·K), subtracted without converting. The factor of 1000 changes a spontaneous reaction into a non-spontaneous one.
| 1 kJ/(mol·K) | 1,000 J/(mol·K) |
Solvers that use molar entropy