The Nernst Equation Calculator helps you determine the cell potential under non-standard conditions. Enter the standard electrode potential, temperature, reaction quotient, and the number of electrons transferred in the reaction to find the cell potential.

Nernst Equation Formula

The Nernst Equation is used to calculate the cell potential of an electrochemical cell under non-standard conditions. The formula is:

E = E0 - (RT / nF) * ln(Q)

Where:

  • E is the cell potential under non-standard conditions (V )
  • E0 is the standard electrode potential (V)
  • R is the gas constant (8.314 J/(mol·K))
  • T is the temperature (K)
  • n is the number of moles of electrons transferred in the reaction
  • F is the Faraday constant (96485 C/mol)
  • Q is the reaction quotient

What is the Nernst Equation?

The Nernst Equation relates the reduction potential of an electrochemical reaction to the standard electrode potential, temperature, and activities (or concentrations) of the chemical species involved. It is essential in the field of electrochemistry for understanding how the potential of an electrochemical cell varies with the conditions such as concentration and temperature.

How to Calculate Cell Potential?

Follow these steps to calculate the cell potential using the Nernst Equation:

  1. Determine the standard electrode potential (E0) for the reaction.
  2. Measure the temperature (T) in Kelvin.
  3. Calculate or find the reaction quotient (Q).
  4. Identify the number of electrons (n) involved in the electrochemical reaction.
  5. Apply the Nernst Equation: E = E0 – (RT / nF) * ln(Q).
  6. Calculate the cell potential by substituting the values into the equation.

Example Problem:

Use the following variables as an example problem to test your knowledge:

Standard Electrode Potential (E0) = 1.23 V

Temperature (T) = 298 K

Reaction Quotient (Q) = 0.1

Number of Electrons (n) = 2

FAQ

1. What is the standard electrode potential?

The standard electrode potential (E0) is the measure of the individual potential of a reversible electrode at standard state, which is with solutes at an effective concentration of 1 mol/L and gases at a pressure of 1 atm, and a temperature of 298 K.

2. How does temperature affect cell potential?

Temperature directly affects the cell potential as shown in the Nernst Equation. An increase in temperature typically increases the cell potential, depending on the reaction quotient and the number of electrons transferred.

3. What is the reaction quotient (Q)?

The reaction quotient (Q) is a measure of the relative amounts of products and reactants present during a reaction at a particular point in time. It is similar to the equilibrium constant but is not necessarily at equilibrium.

4. Can the Nernst Equation be used for different reactions?

Yes, the Nernst Equation can be applied to any electrochemical reaction where the standard electrode potential, temperature, reaction quotient, and number of electrons transferred are known.

5. How accurate is the Nernst Equation Calculator?

The calculator provides an estimate of the cell potential based on the inputs provided. For precise measurements, it is recommended to use laboratory equipment and consider other factors such as activity coefficients and ionic strength.