How does Gibbs energy of a reaction relate to entropy and enthalpy?

1 Answer

The Gibbs free energy equation uses both entropy and enthalpy to calculate the energy produced or used in a reaction.


#DeltaG = DeltaH -TDeltaS#

#DeltaH# = The change in enthalpy or heat energy. Most spontaneous reactions have an increase in heat energy as energy is lost by the reactants and released to the surrounding environment.

#T# = the temperature at which the reaction occurs

#DeltaS# = the change in entropy, or the level of disorder in the system.

In most spontaneous reactions the level of disorder increases.

The Gibbs free energy equation indicates that as time goes on both the amount of heat goes down and the level of disorder increases until there is no usable heat or matter left in the universe.