Why is Gibbs free energy useful?

1 Answer
Dec 30, 2017

Answer:

Why....?

Explanation:

Well, to quote a text-book, the #"Gibbs free energy"# is the single, unequivocal criterion as to the spontaneity of chemical change...

And it is normally introduced by quoting an enthalpy term, and an entropy term...i.e...

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

...and this function can be further related to the thermodynamic equilibrium constant for a given reaction....by the relation....

#lnK_"eq"=(-DeltaG^@)/(RT)#

And quite clearly, ONLY negative #DeltaG^@# values will give rise to a positive #K_"eq"# value, and thus only reactions with negative #DeltaG^@# values are spontaneous.