Calculateur de l'Équation de Nernst Gratuit
Calculez le potentiel de cellule en conditions non standard avec l'équation de Nernst.
Cell Potential (E)
1.1591 V
Cell Potential (E) vs Standard Cell Potential (E°)
Formule
## Nernst Equation ### Formula **E = E° − (RT / nF) × ln(Q)** Where: - **E** = cell potential under non-standard conditions (V) - **E°** = standard cell potential (V) - **R** = 8.314 J/(mol·K) - **T** = temperature (K) - **n** = number of electrons transferred - **F** = 96485 C/mol (Faraday constant) - **Q** = reaction quotient At 25°C this simplifies to: E = E° − (0.0592/n) × log₁₀(Q)
Exemple Résolu
Cu/Zn cell with E° = 1.10 V, n = 2, T = 298 K, Q = 0.01.
- 01E = E° - (RT/nF) × ln(Q)
- 02E = 1.10 - (8.314×298)/(2×96485) × ln(0.01)
- 03E = 1.10 - (0.01285) × (-4.605)
- 04E = 1.10 + 0.0592
- 05E = 1.159 V
Questions Fréquentes
When is the Nernst equation needed?
Use it when concentrations are not 1 M (non-standard conditions). The standard cell potential assumes all concentrations are 1 M.
What happens when Q = 1?
When Q = 1, ln(Q) = 0, so E = E°. Standard conditions correspond to Q = 1.
What happens at equilibrium?
At equilibrium, E = 0 and Q = K. The Nernst equation gives: 0 = E° - (RT/nF)ln(K), which relates E° to K.
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