What is free energy?

1 Answer
Nov 5, 2016

The #"Gibbs Free Energy"# is the fundamental, unequivocal criterion for the spontaneity of chemical change.

Explanation:

Formally, the #"Gibbs Free Energy"# features an enthalpy term, and an entropy term, which is multiplied by absolute temperature.

#DeltaG^@=DeltaH^@-TDeltaS^@#.

This may be related to the thermodynamic equilibrium constant, #K_"eq"#, by the relationship, #lnK_"eq"=(-DeltaG^@)/(RT)#.

If #DeltaG# is negative, the reaction is spontaneous as written. If #DeltaG# is #0#, the reaction is at equilibrium. And if #DeltaG# is positive, the reaction is non-spontaneous.