Nernst equation calculator
The Nernst equation corrects a standard electrode potential for the concentrations actually present.
V
Cell potential
1.129 58V
- Change per decade of Q
- 29.580 mV
Show the working
- Standard cell potential = 1.1
- Electrons transferred = 2
- Reaction quotient Q = 0.1
- Temperature = 25
- tk = 25 + 273.15 = 298.15
- slope = Rgas * 298.15 / (2 * Far) = 0.012 846 3
- Cell potential = 1.1 - 0.012 846 3 * ln(0.1) = 1.129 58
- Change per decade of Q = Rgas * 298.15 / (2 * Far) * ln(10) * 1000 = 29.5797
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
Scenarios & local history
Compare a saved scenario
Recent calculations
The formula
- E = E0 - (R T / n F) ln Q
- F = NA x e = 96485.33212... C/mol, exact
At 25 degrees Celsius and one electron the slope works out at 59.16 mV per decade, the number every electrochemistry course quotes.
Both R and the Faraday constant are exact under the 2019 SI, so the only uncertainty here is in your inputs.