Nernst Equation Calculator

The redox potential or oxidation/reduction potential of a half-cell or full-cell reaction is also known as the reduction potential. It evaluates the susceptibility of molecules (or atoms, ions, and other particles) to acquire electrons and therefore be reduced. This value is expressed in volts (V), which are the same units that Ohm's law calculator uses.

Oxidation/Reduction Potential: When electrons are withdrawn, such as when a free radical steals an electron from a cell, oxidation occurs. On the other hand, Reduction refers to the process of getting or gaining electrons, as when an antioxidant contributes an electron to a free radical.

Reduction Potential: A solution with a greater potential will tend to gain electrons (reduce), while one with a lower potential would prefer to lose electrons (be oxidized). It's worth noting that a high reduction potential doesn't guarantee that the reaction will take place; the reaction still requires some activation energy.

It's tough to assess a solution's absolute potential. As a result, reduction potentials are frequently specified in terms of a reference electrode. The standard reduction potential is the redox potential measured under standard conditions: 25 °C, 1 per ion activity, and 1 bar pressure for each gas involved in the process. The standard reduction potential is defined in terms of a standard hydrogen electrode (SHE), which is given a 0 volts potential randomly.

The reduction potential is related to the standard electrode potential, temperature, and molecular activity using the Nernst equation (cell potential equation). For a rough estimate, concentrations can be used to replace activities. The Nernst equation for a half-cell or full-cell reaction is E = E₀ - RT/zF * ln([red]/[ox])

• Where, E = Reduction potential in volts (V)
• E0 = Standard reduction potential in volts.
• R = Gas constant, R= 8.314 J/(K•mol)
• T = Temperature at which the reaction would occur, is expressed in Kelvins (K);
• z = Number of moles of electrons transferred in the reaction (mol)
• F = Faraday constant, F = (96,485.3 C/mol)
• [red] = Reduced chemical activity of the molecule (atom, ion...). It can be replaced with concentration
• [ox] = Chemical activity of the molecule (atom, ion...) in its oxidised state. Concentration can also be used to replace it.

The following is the procedure how to use the Nernst equation calculator

• Step 1: In the input field, enter the standard half-cell reduction potential, chemical activity for the reductant and oxidant species, and the number of moles of electrons exchanged.
• Step 2: To calculate the reduction potential, click the "Calculate" button.
• Step 3: Finally, the Nernst equation's reduction potential will be displayed in the output field.

1. What is the result of the Nernst Equation?

Based on the charge on the ion (i.e., its valence) and the concentration gradient across the membrane, the Nernst equation derives the equilibrium potential (also known as the Nernst potential) for an ion.

2. Which value Cannot be calculated using the Nernst Equation?

Another flaw in this equation is that it cannot be utilised to determine cell potential while the electrode is conducting current. This is because the current flow changes the activity of the ions on the electrode's surface.

3. How does the Nernst Equation calculate Equilibrium Potential?

RMP is based on the Nernst Equation. The concentration gradient of each ion across the membrane determines its equilibrium potential. If the concentrations on both sides were equal, the force of the concentration gradient would be zero, and the equilibrium potential would also be zero.

4. Is temperature a factor in the Nernst Equation?

The Nernst equation is unaffected by temperature. The change in cell potential is proportional to the change in temperature. If the reaction quotient is not one and the other factors remain constant, the cell potential drops as the temperature rises.