Free Energy
| Formula / Notation | G = H − TS; ΔG = ΔH − TΔS; ΔG < 0 → spontaneous |
|---|---|
| Also Known As | Gibbs energy, Gibbs free energy (G), free energy, Gibbs function |
What is Free Energy?
The thermodynamic potential (Gibbs free energy, G) that measures the maximum work extractable from a system at constant temperature and pressure. ΔG = ΔH - TΔS. Negative ΔG indicates a spontaneous process. Free energy connects enthalpy, entropy, and spontaneity.
Formula & Notation
Other Names / Synonyms: Gibbs energy, Gibbs free energy (G), free energy, Gibbs function
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
The thermodynamic potential (Gibbs free energy, G) that measures the maximum work extractable from a system at constant temperature and pressure. ΔG = ΔH - TΔS. Negative ΔG indicates a spontaneous process. Free energy connects enthalpy, entropy, and spontaneity.
Gibbs free energy is used to predict reaction spontaneity, calculate equilibrium constants (ΔG° = −RT ln K), determine battery cell potentials (ΔG = −nFE), design thermodynamic cycles, evaluate phase stability, and assess biological energy changes in metabolism (ATP hydrolysis ΔG).
Reactions with large negative ΔG (highly spontaneous, large exothermic ΔH component) tend to proceed rapidly and exothermically, posing explosion or fire risk. However, ΔG tells only about thermodynamic spontaneity, not rate — kinetic barriers can slow even highly favourable reactions to safe speeds…
The formula or notation for Free Energy is: G = H − TS; ΔG = ΔH − TΔS; ΔG < 0 → spontaneous