Change In Free Energy Calculator

Enter Change in Enthalpy (ΔH):

Enter Temperature (T) in Kelvin:

Enter Change in Entropy (ΔS):

Calculate

Change in Free Energy (ΔG):

The Change In Free Energy Calculator helps determine Gibbs free energy change in a chemical reaction. This is essential for predicting spontaneity and feasibility of reactions.

Formula

The formula for calculating the change in free energy is:

ΔG = ΔH − TΔS

Where:

• ΔG = Change in Free Energy
• ΔH = Change in Enthalpy
• T = Temperature in Kelvin
• ΔS = Change in Entropy

How to Use

1. Enter the change in enthalpy (ΔH).
2. Enter the temperature in Kelvin (T).
3. Enter the change in entropy (ΔS).
4. Click the “Calculate” button.
5. The result will display the change in free energy (ΔG).

Example

If the change in enthalpy is 100 kJ, the temperature is 300K, and the change in entropy is 0.2 kJ/K, then:

ΔG = 100 – (300 × 0.2) = 40 kJ

So, the change in free energy is 40 kJ.

FAQs

1. What is free energy in thermodynamics?
   Free energy represents the usable energy in a system available to do work.
2. Why is ΔG important?
   It helps determine whether a chemical reaction is spontaneous or non-spontaneous.
3. What does a negative ΔG indicate?
   A negative ΔG means the reaction occurs spontaneously.
4. What does a positive ΔG indicate?
   A positive ΔG means the reaction is non-spontaneous.
5. What happens if ΔG is zero?
   The system is in equilibrium, meaning no net reaction occurs.
6. Does temperature affect ΔG?
   Yes, an increase in temperature can make a reaction more or less spontaneous.
7. What are standard conditions for ΔG calculations?
   Standard conditions are 298K temperature, 1 atm pressure, and 1 M concentration.
8. Can ΔG be used in biological systems?
   Yes, it helps in understanding metabolic reactions and energy transfer.
9. How does entropy affect free energy?
   A higher entropy change (ΔS) reduces ΔG, increasing spontaneity.
10. Is free energy the same as enthalpy?
    No, enthalpy (ΔH) includes total energy, while free energy (ΔG) is the usable part.
11. Can ΔG predict reaction speed?
    No, ΔG determines spontaneity but not reaction kinetics.
12. What is the relationship between ΔG and equilibrium constant?
    ΔG is related to the equilibrium constant (K) through the Gibbs free energy equation.
13. How is ΔG different from Helmholtz free energy?
    Gibbs free energy applies to constant pressure, while Helmholtz free energy is for constant volume.
14. Can ΔG be calculated for phase changes?
    Yes, ΔG helps in analyzing melting, boiling, and sublimation processes.
15. What role does ΔG play in electrochemical cells?
    It helps determine the feasibility and voltage of electrochemical reactions.
16. Does ΔG depend on concentration?
    Yes, ΔG changes based on reactant and product concentrations.
17. Can ΔG be directly measured?
    No, it is calculated using enthalpy, entropy, and temperature.
18. How does ΔG affect living organisms?
    It determines energy transfer in cellular processes like ATP production.
19. What is the unit of ΔG?
    The unit is usually kJ/mol or J/mol.
20. Is ΔG the same for exothermic and endothermic reactions?
    No, exothermic reactions tend to have negative ΔG, while endothermic reactions can have positive ΔG.

Conclusion

The Change In Free Energy Calculator is an essential tool for determining reaction feasibility and spontaneity. Understanding ΔG is crucial in chemistry, biology, and physics for analyzing energy changes in different systems.