Electrochemical Cell Calculator: Cell Potential, Nernst Equation, Delta G, K and Faraday's Laws of Electrolysis
Galvanic cells and electrolysis, with the working.
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How this calculator works
Choose the standard cell, the Nernst equation, or electrolysis.
Enter the half-cell potentials and the electrons transferred, or the current, time and molar mass.
The calculator gives the potential, free energy, K, or the mass deposited.
Formulas used
- E^\circ_{cell} = E^\circ_{cathode} - E^\circ_{anode}
- \Delta G^\circ = -nFE^\circ
- E = E^\circ - \frac{RT}{nF}\ln Q
- m = \frac{MIt}{zF}
Worked example
With the default numbers in the calculator above:
- Standard cell potential: cathode minus anode: 1.1 V
- Standard Gibbs free energy change: -212.268 kJ per mole of reaction
- Equilibrium constant: 1.5406e+37 (log10 K = 37.188)
Change the numbers in the calculator to see the full working, every step, for your own case.
A second worked example
A different case, with these numbers: What do you want? Cell potential by the Nernst equation.
- Standard cell potential: cathode minus anode: 1.1 V
- The factor RT/F at that temperature: 0.0256926 V
- Cell potential under these conditions (Nernst equation): 1.15916 V
- The same using log base 10 at 25 C: 1.15916 V
Common questions
How do I find the cell potential?
Subtract the standard reduction potential of the anode from that of the cathode.
What does the Nernst equation do?
It corrects the standard cell potential for the actual concentrations and temperature, using the reaction quotient Q.
What are Faraday's laws?
The mass deposited in electrolysis is proportional to the charge passed, and to the molar mass divided by the number of electrons per ion.
Related calculators
Got a question about this? Ask an engineering question and get a plain-language answer with references.
Further reading: Any first-year chemistry text (electrochemistry). Check the potentials against your own data table.
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