Now when we discuss Gibbs free energy and equilibrium, we're really making a comparison between Gibbs free energy and our equilibrium constant. Now here we're going to say the relationship between our Gibbs free energy which is delta G_{0} and our equilibrium constant which is K and we'll say EQ. Can also be observed in the following formula.

Here we're going to say use this formula when your equilibrium constant K_{AQ} is given or can be calculated. Here are the formula Is that the change in our standard Gibbs free energy equals negative RT lnK. And here we're talking about K_{eq}. Here R would be our gas constant, which we've seen in the past. It's equal to 8.314 Joules over moles times K.

Remember, we employ this type of R constant whenever we're talking about energy, velocity, or speed. In this section, we're not really talking about velocity or speed, we're talking about energy because we're using the units of either joules or kilojoules. So just keep that in mind. When we're talking about joules or kilojoules, then we're using the R value in the form of 8.314 joules over moles times K.

ΔG = − R T ln K