Standard Cell Potential

[IsabelMurillo3K]

Hey guys!
I was wondering if anyone could help me understand the relationship between standard cell potential and equilibrium constant of a reaction?
Thank you!

[Najia Saleem 2G]

Sometimes, a picture is worth a thousand words. I believe the equation I have attached best summarizes the relationship between standard cell potential and the equilibrium constant of a reaction.

[JonathanM]

Hey! So there is just an equation relating the two for a redox reaction that is, E^o=(RT/nF)ln(K) or if you solve for K, K=e^(nFE^o/RT), but the equation isn't super intuitive or give you much insight as to why the standard cell potential is related to K. We can start by saying that nFE_cell is an expression that gives that maximum amount of work that can be done by the transfer of electrons in the reaction, which is related to delta G. Delta G^o is equal to -nFE^o_cell but it is also equal to -RT Ln(K). We can then set these equal to each other and get the original equation relating E^o and K. So basically they are related because both of them are related to delta G and as such they can be related to each other. Hope this helps!

[Kiara Phillips 3L]

Isolating each of the variables, Increasing T increases cell potential, decreasing it decreases cell potential. If nF is increased E of the cell decreases whereas if nF decreases Ecell increases.Same thing for ln(K) because ultimately it is a value that you are multiplying your fraction by.