Gibb’s Free Energy ‘G’

The free energy of a chemical system ‘G’ is the energy which is available to do work.

Free energy is the driving force that brings about a chemical change. The standard free energy change ∆G^Ꝋ is a state function because it depends on the initial and final state of the system.

∆G^Ꝋ = G^Ꝋ₂ – G₁^Ꝋ

∆G^Ꝋ = G^Ꝋ[Product] – G^Ꝋ [Reactant]

Gibb’s free energy takes into consideration the effects of enthalpy and entropy factors as represented in the relationship.

G = H – TS

For change at constant temperature: ∆G = ∆H – T∆S^Ꝋ

∆H = Enthalpy change 

∆G = Gibbs free energy change