Gibbs Free Energy of Formation

You can use standard enthalpy change (ΔH°) and standard absolute entropy (S°) data to calculate the change in Gibbs free energy (ΔG°) for a chemical reaction or physical change using the equation:

 ΔG° = ΔH° - TΔS°

... OR ....
you can use tables of values for the standard Gibbs free energy of formation of compounds (ΔG_ƒ°).
For a chemical reaction or physical change:

reactants → products 

ΔG° = ΣΔG_ƒ°(products) - ΣΔG_ƒ°(reactants)

If you would like to understand where this comes from and how it can be applied solve problems in chemistry, visit our new tutorial Standard Gibbs Free Energy of Formation Calculations

AUS-e-TUTE Members should log-in to use the new tutorial, game, test and exam resources.

Introduction to Entropy

What is entropy?
What is meant by a chemical system having low entropy or high entropy?
What is the relationship between disorder, energy and entropy?

If you are asking these questions, then you will find AUS-e-TUTE's new entropy introductory tutorial, game and test very helpful! AUS-e-TUTE Members should log in to use these new resources (under the topic heading Thermodynamics in the Test Centre).

Not an AUS-e-TUTE Member?
A "free-to-view" tutorial is currently available at http://www.ausetute.com.au/entropy.html