Formula Used:
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Definition: The standard cell potential is the potential difference between two half-cells under standard conditions (1M concentrations, 1 atm pressure, 25°C).
Purpose: It helps predict the direction of electron flow and the spontaneity of redox reactions in electrochemical cells.
The calculator uses the formula:
Where:
Explanation: The negative of the Gibbs free energy change is divided by the product of moles of electrons and Faraday's constant.
Details: This calculation is fundamental in electrochemistry for determining cell voltages, predicting reaction spontaneity, and designing batteries.
Tips: Enter the standard Gibbs free energy change (ΔG°) in joules and moles of electrons transferred (n). The moles of electrons must be > 0.
Q1: What does a positive E°cell indicate?
A: A positive standard cell potential indicates a spontaneous reaction under standard conditions.
Q2: How do I find ΔG° for a reaction?
A: ΔG° can be calculated from standard formation energies or from the equation ΔG° = ΔH° - TΔS°.
Q3: What's the significance of the Faraday constant?
A: It represents the electric charge carried by one mole of electrons (approximately 96485 C/mol).
Q4: Can this calculator be used for non-standard conditions?
A: No, this calculates standard potential only. For non-standard conditions, use the Nernst equation.
Q5: What are typical values for standard cell potentials?
A: Most electrochemical cells have potentials between -3V and +3V, though some special cells may fall outside this range.