So far we have treated standard free energies and equilibrium constants as if they were independent, experimentally measured quantities, and entirely separate criteria for looking at a reaction. They actually are not independent; if you know one, you can calculate the other.

You may have noticed from the ammonia reaction and other examples in this chapter that as becomes more negative, indicating greater spontaneity, , becomes larger, representing a greater excess of products over reactants at equilibrium. Conversely, when is zero, is 1.00, and as becomes more positive, falls below 1.00:






This suggests a logarithmic relationship.