Standard electrode potential of SHE at 298 K is :

Options

A. 0.05V
B. 0.10V
C. 0.50V
D. 0.00V

Answer

To determine the standard electrode potential of the Standard Hydrogen Electrode (SHE) at 298 K, we can follow these steps:

### Step-by-Step Solution

1. **Understanding the Standard Hydrogen Electrode (SHE)**:
- The SHE is a reference electrode used to measure the electrode potentials of other half-cells. It is based on the half-reaction where hydrogen ions (H⁺) gain electrons to form hydrogen gas (H₂).

2. **Writing the Half-Reaction**:
- The half-reaction for the SHE is:
\[ 2 \text{H}^+ (aq) + 2 e^- \rightarrow \text{H}_2 (g) \]

3. **Applying the Nernst Equation**:
- The Nernst equation relates the cell potential (E) to the standard electrode potential (E⁰) and the concentrations of the reactants and products:
\[ E = E^0 - \frac{0.0591}{n} \log \left( \frac{[\text{Products}]}{[\text{Reactants}]} \right) \]
- For the SHE, we have:
- \( E^0 \) is the standard electrode potential we want to find.
- \( n \) (the number of electrons transferred) is 2.

4. **Substituting Values into the Nernst Equation**:
- For the SHE, we assume:
- The partial pressure of H₂ gas = 1 atm
- The concentration of H⁺ ions = 1 M
- Therefore, substituting these values into the Nernst equation gives:
\[ E = E^0 - \frac{0.0591}{2} \log \left( \frac{1}{1^2} \right) \]
- Since \(\log(1) = 0\), the equation simplifies to:
\[ E = E^0 \]

5. **Determining the Standard Electrode Potential**:
- By convention, the standard electrode potential of the SHE is defined as 0 V. Therefore:
\[ E^0 = 0 \text{ V} \]

### Conclusion
The standard electrode potential of the Standard Hydrogen Electrode (SHE) at 298 K is **0 V**.