What is the Standard electrod potential in chemistry class 12th
🔹 What is Standard Electrode Potential in Chemistry?
Standard Electrode Potential (denoted as E°) is the electric potential (voltage) of a half-cell (electrode) measured under standard conditions when it is connected to the Standard Hydrogen Electrode (SHE), which is assigned a potential of 0.00 volts.
🔹 Definition:
Standard Electrode Potential (E°) is the potential developed by an electrode when it is in equilibrium with its ions at 1 M concentration, 1 atm pressure, and 25°C (298 K), compared to the Standard Hydrogen Electrode (SHE).
🔹 Standard Conditions:
- Temperature = 25°C (298 K)
- Concentration of ions = 1 M
- Pressure of gases = 1 atm
- Electrode connected to Standard Hydrogen Electrode (SHE)
🔹 Notation:
- Represented as E°ₘ/ₘⁿ⁺ or E°(half-cell)
- Measured in volts (V)
🔹 Example Values:
Electrode | Half-cell Reaction | E° (V) |
---|---|---|
Cu²⁺/Cu | Cu²⁺ + 2e⁻ → Cu | +0.34 V |
Zn²⁺/Zn | Zn²⁺ + 2e⁻ → Zn | –0.76 V |
H⁺/H₂ (SHE) | 2H⁺ + 2e⁻ → H₂ | 0.00 V |
🔹 Interpretation:
- Positive E° value: Electrode has a high tendency to get reduced (strong oxidizing agent).
- Negative E° value: Electrode has a high tendency to get oxidized (strong reducing agent).
🔹 Importance:
- Helps predict the feasibility of redox reactions
- Used to construct electrochemical cells
- Determines cell potential (E°cell) using:
E°_{\text{cell}} = E°_{\text{cathode}} - E°_{\text{anode}}
Would you like help calculating E°cell or using a standard electrode potential chart?
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