Nernst Equation

[Grace Kim 1a]

I know there are two different nernst equations, the one where there is a log and another where there is a ln. How do I know which equation to use?

[Claude Chung 2F]

hello -- so we use the Nernst equation with log when dealing with concentrations in molarity, and then we use the Nernst equation with ln when dealing with concentrations expressed in activity.

[sarahd]

The one with log can be used when there are standard conditions present, hence why we don't see R or T in the equation. The one with ln and Q is for non-standard conditions not at equilibrium.