Gibbs Free Energy A Measure of Stability

In summary, Gibbs free energy is a measure of a substance's ability to react or change spontaneously. A negative change in Gibbs free energy indicates the likelihood of a spontaneous reaction, with a more negative value indicating a higher likelihood. However, there is some conflicting information in regards to stability, as a smaller Gibbs free energy is also associated with higher stability. Ultimately, a positive Gibbs free energy indicates a non-spontaneous reaction, while a more negative value suggests a greater likelihood of spontaneity."
  • #1
Bashyboy
1,421
5
Hello everyone,

I am having a little difficulty understand precisely what Gibbs free energy is. I have read in my textbook that a negative change in Gibbs free energy implies that the substance under consideration will react/change spontaneously. As such, the more negative the Gibbs free energy is, the more spontaneously the reaction/occurs. However, at another point in the book, the author states that the smaller the Gibbs free energy is, the more stable it is. This two ideas seem to be conflicting...
 
Physics news on Phys.org
  • #2
Bashyboy said:
Hello everyone,

I am having a little difficulty understand precisely what Gibbs free energy is. I have read in my textbook that a negative change in Gibbs free energy implies that the substance under consideration will react/change spontaneously. As such, the more negative the Gibbs free energy is, the more spontaneously the reaction/occurs. However, at another point in the book, the author states that the smaller the Gibbs free energy is, the more stable it is. This two ideas seem to be conflicting...
If the Gibbs free energy is positive, the reaction will not proceed spontaneously. If it is negative, it is capable of proceeding spontaneously. The actual likelihood that it will proceed spontaneously increases as the Gibbs free energy gets more negative ie. as the magnitude of the negative Gibbs free energy increases.

AM
 

1. What is Gibbs Free Energy?

Gibbs Free Energy is a thermodynamic property that measures the amount of energy available in a system to do work. It takes into account both the enthalpy (heat energy) and entropy (disorder) of a system.

2. How is Gibbs Free Energy related to stability?

Gibbs Free Energy is a measure of a system's stability. Systems with lower Gibbs Free Energy values are more stable, as they have less energy available to undergo spontaneous change.

3. What is the equation for calculating Gibbs Free Energy?

The equation for Gibbs Free Energy is ΔG = ΔH - TΔS, where ΔG is the change in Gibbs Free Energy, ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy.

4. How does temperature affect Gibbs Free Energy?

Temperature has a significant effect on Gibbs Free Energy. As temperature increases, the value of ΔS (change in entropy) also increases, resulting in a decrease in ΔG (Gibbs Free Energy). This means that at higher temperatures, a system is less stable and more likely to undergo spontaneous change.

5. Can Gibbs Free Energy be negative?

Yes, Gibbs Free Energy can be negative. This indicates that the system has a lower energy state and is more stable. However, it is important to note that a negative ΔG does not necessarily mean that a reaction will occur, as other factors such as activation energy also play a role in determining the spontaneity of a reaction.

Similar threads

Replies
4
Views
1K
Replies
3
Views
843
Replies
15
Views
5K
  • Biology and Chemistry Homework Help
Replies
1
Views
2K
Replies
1
Views
1K
Replies
10
Views
2K
Replies
1
Views
2K
Replies
8
Views
2K
Replies
6
Views
2K
Replies
11
Views
2K
Back
Top