Concept preview

What you will be able to do

1. 01Understand the relationship between Gibbs Free Energy, enthalpy, and entropy.
2. 02Calculate Gibbs Free Energy changes for chemical reactions under standard and non-standard conditions.
3. 03Predict the spontaneity of a reaction using Gibbs Free Energy.
4. 04Analyse the temperature dependence of reaction spontaneity using Gibbs Free Energy.

The concept of Gibbs Free Energy ($\text{G}$) is central to understanding chemical thermodynamics. It combines the principles of enthalpy ($\text{H}$) and entropy ($\text{S}$) to predict the spontaneity of a process. Spontaneity refers to whether a process can occur without external intervention. Gibbs Free Energy is a state function, meaning its value depends only on the initial and final states of a system, not on the path taken. The change in Gibbs Free Energy ($\text{ΔG}$) is given by the equation $\text{ΔG} = \text{ΔH} - T\text{ΔS}$, where $T$ is the temperature in Kelvin. This equation provides a criterion for spontaneity: a negative $\text{ΔG}$ indicates a spontaneous process, while a positive $\text{ΔG}$ suggests non-spontaneity.