What is the standard electrode potential?

The standard electrode potential (E°) is a measure of the tendency of a chemical species to gain or lose electrons under standard conditions. In simpler terms, it tells us how easily a substance gets reduced or oxidized.

Key Points:

1. Definition:
   • It is the voltage of an electrode when it is connected to a standard hydrogen electrode (SHE) under standard conditions:
     • 1 M concentration of ions
     • 1 atm pressure for gases
     • 25°C (298 K) temperature
2. Sign Convention:
   • Positive E°: The substance easily gains electrons (strong oxidizing agent).
   • Negative E°: The substance loses electrons easily (strong reducing agent).
3. Measurement:
   • Measured by connecting the electrode to the standard hydrogen electrode and recording the potential difference.
4. Applications:
   • Predict the direction of redox reactions.
   • Determine the feasibility of electrochemical reactions.
   • Used in designing batteries and fuel cells.

In short: Standard electrode potential tells us how strongly a species wants to be reduced compared to hydrogen under standard conditions.