The Nernst equation is a formula that relates the cell potential of an electrochemical cell to the concentrations (or pressures) of the reactants and products. In simple terms, it tells us how the voltage of a cell changes when conditions are not standard.
Explanation:
- Standard cell potential (E°) is measured under standard conditions (1 M concentration, 1 atm pressure, 25°C).
- In real-life situations, concentrations and pressures may vary. The Nernst equation adjusts the cell potential to account for these changes.
- It helps predict whether a reaction will occur and the actual voltage of a battery or cell under working conditions.
Key Points:
- Works for any redox reaction.
- Shows that higher concentration of reactants increases cell potential, while higher concentration of products decreases it.
- Important in biological systems, batteries, and sensors.
In short: The Nernst equation calculates the real voltage of a cell depending on the concentrations of chemicals, not just standard conditions.