व्यावहारिक

गिब्ज मुक्त ऊर्जा

⚡Gibbs Free Energy (ΔG=ΔH-TΔS)

ΔH (kJ/mol)

T (K)

ΔS (J/mol·K)

What is Gibbs Free Energy?

▾

Gibbs free energy (G) determines whether a chemical reaction can occur spontaneously at constant temperature and pressure. ΔG = ΔH − TΔS: negative ΔG means spontaneous; positive means non-spontaneous.

DigiCalcs delivers precision-engineered tools for engineers and STEM professionals.

How to Gibbs Free Energy

▾

1ΔG = ΔH − TΔS
2ΔH = enthalpy change (bond energies)
3T = temperature in Kelvin
4ΔS = entropy change (disorder)
5ΔG < 0: spontaneous; ΔG > 0: non-spontaneous; ΔG = 0: equilibrium

Worked Examples

▾

Example 1

Given:ΔH=−200kJ · T=298K · ΔS=+150J/K

परिणाम:ΔG = −200−(298×0.15) = −244.7 kJ → spontaneous

Both enthalpy and entropy favour spontaneity

Special Cases

▾

Temperature-dependent spontaneity

When ΔH and TΔS have opposite signs, temperature determines spontaneity. Endothermic reactions with positive ΔS become spontaneous at high T; exothermic reactions with negative ΔS become spontaneous at low T.

⭐

Did you know?

Josiah Willard Gibbs developed this function in 1873–1876 — arguably the most significant contribution to chemistry in the 19th century, enabling prediction of chemical equilibria.

References

›Gibbs free energy — Wikipedia