Calculate cell potential at non-standard concentrations using the Nernst equation.
The Nernst equation corrects standard potential for actual concentrations. The 59.2 mV per decade slope at 25 °C is what makes pH electrodes work, since each pH unit shifts the potential by that amount. Nernst slope is temperature dependent, which is why pH meters require temperature compensation for accurate readings.
Nernst Equation
E = E° − (RT ÷ nF) ln Q, giving 59.2 mV per decade at 25 °C for n = 1
E = E° − (RT ÷ nF) ln Q, giving 59.2 mV per decade at 25 °C for n = 1 The Nernst equation corrects standard potential for actual concentrations. The 59.2 mV per decade slope at 25 °C is what makes pH electrodes work, since each pH unit shifts the potential by that amount.
Nernst slope is temperature dependent, which is why pH meters require temperature compensation for accurate readings.
This calculator takes 4 inputs: Standard cell potential, Electrons transferred, Reaction quotient, Temperature. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.