Free Energy

[Marsenne Cabral 1A]

Why is the delta G for a spontaneous process negative always?

[ryanhon2H]

Gibbs free energy is given by the equation ∆G = ∆H - T∆S

An exothermic reaction is much more likely to be spontaneous than an endothermic reaction, as it releases heat instead of requiring it. The ∆H of an exothermic and likely spontaneous reaction is negative.

A reaction that also increases entropy will also likely be spontaneous as well. An increase in entropy is represented by a positive ∆S.

So if ∆H is negative and ∆S is positive for a spontaneous reaction, we can see that by putting those terms into the equation, ∆G must be negative as well