How to Calculate Non-Standard Cell Voltage (E)
Calculate concentration-dependent cell potential step-by-step:
Enter E°cell
Input standard cell voltage E°cell in Volts.
Enter Electron Transfer n
Input number of moles of electrons n transferred in balanced redox equation.
Enter Reaction Quotient Q
Input concentration quotient Q = [Products] / [Reactants].
Compute Non-Standard E
Subtract E = E° - (0.05916 / n) × log10(Q) at 298.15 K.
Key Features & Nernst Electrochemistry
Concentration-Dependent Engine
Computes cell potential changes as battery discharges or reactants deplete.
Equilibrium Constant (Keq)
Calculates thermodynamic equilibrium constant Keq when E = 0.
Battery Discharge Monitor
Illustrates why batteries lose voltage as Q approaches Keq.
Electrochemistry Guide: The Nernst Equation
Formulated by Walther Nernst in 1889, the Nernst Equation calculates the electromotive force (cell voltage E) under non-standard concentration conditions:E = E°cell - [(R · T) / (n · F)] · ln(Q)At 25°C (298.15 K), it simplifies to E = E°cell - (0.05916 / n) · log₁₀(Q).
Frequently Asked Questions
?What happens when a battery dies (E = 0)?
When a battery dies, the reaction reaches chemical equilibrium (Q = Keq). At this point, non-standard voltage E = 0 Volts, and no net current can be drawn.