Gibbs Free Energy Calculator
Gibbs free energy calculator
Calculate Gibbs free energy change from enthalpy, entropy, and temperature.
Result
ΔG = -49.422 kJ/mol
Negative ΔG indicates thermodynamically favorable direction.
Chem signal
Advanced options
Flow
- Enter ΔH in kJ/mol and ΔS in J/mol·K.
- Enter absolute temperature in Kelvin.
- Read ΔG result and spontaneity hint.
Example
Worked example: ΔH = -85.2 kJ/mol, ΔS = -120 J/mol·K, T = 298.15 K
- 1 Convert TΔS term to kJ/mol: 298.15 × (-120) / 1000.
- 2 Subtract TΔS from ΔH.
- 3 Result ΔG is negative under these conditions.
ΔG ≈ -49.42 kJ/mol.
How
- Enter ΔH in kJ/mol and ΔS in J/mol·K.
- Enter absolute temperature in Kelvin.
- Read ΔG result and spontaneity hint.
Avoid
- Forgetting entropy units and missing J to kJ conversion.
- Using Celsius instead of Kelvin for temperature.
Checks
Best fit
Gibbs Free Energy Calculator is built for calculate gibbs free energy change from enthalpy, entropy, and temperature. If Gibbs Free Energy Calculator does not match the input scope, compare the answer with a second method.
Input check
Match the entered values to this rule before copying the answer: ΔG = ΔH - TΔS.
Sanity check
For Gibbs Free Energy Calculator, use the worked example as a quick benchmark: ΔG ≈ -49.42 kJ/mol. If the gibbs free energy calculator answer is far away, check whether an input, unit, or mode changed.
Before copying
Review this common issue first: forgetting entropy units and missing j to kj conversion.
Ref only. Verify values. Follow lab safety.
FAQ
What does negative ΔG indicate?
Negative ΔG suggests thermodynamically favorable direction under stated conditions.
Can ΔG change with temperature?
Yes. The TΔS term directly shifts Gibbs free energy.
Is this kinetic prediction?
No. Gibbs free energy addresses thermodynamic tendency, not reaction speed.
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