Gibbs Free Energy Formula:
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Definition: Gibbs free energy (ΔG) is a thermodynamic potential that measures the maximum reversible work that may be performed by a thermodynamic system at constant temperature and pressure.
Purpose: It helps predict whether a process will occur spontaneously at constant pressure and temperature.
The calculator uses the formula:
Where:
Explanation: The negative sign indicates that the free energy of the system decreases when work is done by the system on the surroundings.
Details: Gibbs free energy is crucial in electrochemistry, chemical thermodynamics, and predicting reaction spontaneity. A negative ΔG indicates a spontaneous process.
Tips: Enter the electrochemical work done by the system in Joules. The calculator will compute the corresponding change in Gibbs free energy.
Q1: Why is there a negative sign in the formula?
A: The negative sign indicates that when the system does work on its surroundings, its free energy decreases.
Q2: What are typical values for electrochemical work?
A: Values vary widely depending on the system, but common electrochemical cells might have work values from a few Joules to several kJ.
Q3: How does this relate to cell potential?
A: For electrochemical cells, ΔG = -nFE, where n is moles of electrons, F is Faraday's constant, and E is cell potential.
Q4: What does a positive ΔG indicate?
A: A positive ΔG means the process is non-spontaneous under the given conditions.
Q5: Can this be used for non-electrochemical systems?
A: Yes, the relationship ΔG = -w applies to any reversible work done at constant temperature and pressure.