Data Source and Methodology
All calculations adhere to the standard thermodynamic principles as outlined in Chemistry LibreTexts. All calculations are strictly based on the provided formulas and data.
The Formula Explained
ΔG = ΔH - TΔS
Glossary of Variables
- ΔH (Enthalpy Change): The heat content change of the system at constant pressure.
- T (Temperature): The absolute temperature in Kelvin.
- ΔS (Entropy Change): The change in entropy, a measure of disorder or randomness.
- ΔG (Gibbs Free Energy): The energy associated with a chemical reaction that can be used to do work.
How It Works: A Step-by-Step Example
Consider a reaction with ΔH = 100 kJ/mol, T = 298 K, ΔS = 200 J/(mol·K). The Gibbs Free Energy is calculated as follows:
ΔG = 100 kJ/mol - 298K * 0.2 kJ/(mol·K) = 40.4 kJ/mol
Frequently Asked Questions (FAQ)
What is Gibbs Free Energy?
Gibbs Free Energy is a thermodynamic quantity that can predict the direction of chemical reactions under constant temperature and pressure.
How is Gibbs Free Energy calculated?
It is calculated using the formula: ΔG = ΔH - TΔS, where ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy.
Why is Gibbs Free Energy important?
It helps in determining whether a process will occur spontaneously under constant temperature and pressure.
What units are used in Gibbs Free Energy calculation?
The typical units used are kJ/mol for ΔG and ΔH, and J/(mol·K) for ΔS.
Can Gibbs Free Energy be negative?
Yes, a negative ΔG indicates that the process can occur spontaneously.