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Nernst Equation Calculator

Find the cell potential at your concentrations from E°, n, Q, and temperature.

 

 

 

 

E (V)

About this calculator

Use this calculator in an electrochemistry lab when the standard potential is in a table, Q is from the bottle concentrations, and you need E now.

The calculation is E = E° − (RT/nF) ln Q, with R = 8.314 J/(mol·K) and F = 96485 C/mol. n is moles of electrons in the balanced half-reaction. Q is dimensionless as written in the Nernst equation. Temperature may be entered in °C or °F; the calculator converts to kelvin. The usual default is 25 °C.

This is the full RT form, not the 25 °C shortcut 0.059/n log₁₀ Q. It is not a liquid-junction correction.

E° (V): Standard cell (or half-cell) potential in volts, 0.34 for Cu²⁺/Cu.

n (e−): Electrons in the balanced reaction. 2 for Cu²⁺ + 2e⁻ → Cu.

Q: Reaction quotient Q, already computed. 1 at standard state.

Temperature: Cell temperature in °C or °F.

E (V): Cell potential in volts at that Q and T.