Standard reduction potential is calculated at

Options

A. `27^(@)C`
B. `25^(@)C`
C. `0^(@)C`
D. `100^(@)C`

Answer

To solve the question regarding the calculation of standard reduction potential, we can follow these steps:

### Step-by-Step Solution:

1. **Definition of Standard Reduction Potential (E°)**:
- The standard reduction potential (E°) is a measure of the tendency of a chemical species to be reduced, which means to gain electrons. It is a key concept in electrochemistry.

2. **Conditions for Measurement**:
- Standard reduction potential is measured under specific standard conditions. These conditions include:
- Concentration of ions: 1 mole per decimeter cubed (1 M).
- Pressure: 1 atmosphere (1 atm).
- Temperature: 25 degrees Celsius (298 K).

3. **Reference Electrode**:
- The standard reduction potential is measured with respect to a reference electrode, which is the Standard Hydrogen Electrode (SHE). The SHE is assigned a potential of 0 volts at standard conditions.

4. **Calculation Context**:
- When calculating the standard reduction potential of a reversible electrode, the above conditions must be satisfied. If they are met, the E° value can be determined relative to the SHE.

5. **Conclusion**:
- Therefore, the standard reduction potential is calculated at standard conditions (1 M concentration, 1 atm pressure, and 25°C) with reference to the Standard Hydrogen Electrode.

### Final Answer:
The standard reduction potential is calculated at standard conditions: 1 M concentration of ions, 1 atm pressure, and 25°C, with reference to the Standard Hydrogen Electrode (SHE).

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