16.5Potential, Free Energy, and Equilibrium
Section · module m68824
What this needs
Learn these first — this section will not make sense without them.
The practical Nernst/K formulas swap natural log for base-10 log via the 0.0592 V factor (0.0592 = RT ln10/F at 298 K) — using the formula correctly means recognizing this as a change-of-base substitution, not a different equation.
Getting K from E°cell = (RT/nF) ln K requires isolating K by exponentiating both sides — worked here as K = 10^(nE°cell/0.0592) — the same exponential-equation move used for ΔG°/K conversions, now driven by a measured cell potential instead of a tabulated free energy.
What this touches
Algebra that turns up here. Not a blocker, but this is where you will see it used.
- Applies4.2Linear Functions
The Nernst equation Ecell = E°cell − (0.0592 V/n) log Q is a linear function of log Q with slope −0.0592/n and intercept E°cell — recognizing this linear structure is what lets a student predict how Ecell moves as Q changes without recomputing from scratch each time.