Nernst Equation

[Maegan Abutin 2C]

Hi. Can someone please explain and breakdown the two Nernst equations? Where do they differ in concept and application? Also, how do these equations relate to Gibbs free energy? Thanks!

[405981594]

There are 2 Nernst equations, one with the standard energy and one without (because electrolytic cells do not have a standard cell potential). The main difference is just with the types of cells used; galvanic or electrolytic. For galvanic cells, when the reaction quotient Q equals the equilibrium constant K, ΔG is zero, and the cell potential equals the standard cell potential. For electrolytic cells, the sign of ΔG determines the direction in which the reaction proceeds; positive ΔG indicates a non-spontaneous reaction, and negative ΔG indicates a spontaneous reaction.

[Aminta Chem]

In the case we aren't given the values to calculate Q or K can were we 1 or -1 to represent Q and K?