Question

In the relationship between `DeltaG` and K for a given reaction, if `DeltaG` is negative, what is K?

Answer 1

Consider a hypothetical reaction:

A ↔ B

The change in free energy, ΔG can be related to the equilibrium constant K as:

ΔG = -RT ln K

i.e.   K = exp (-ΔG/RT)

When ΔG is negative, the exponential becomes positive which results in a high value of the equilibrium constant (K).  More and more of the reactants get converted into products and the reaction tends to be spontaneous.