Consider the cell potentials `E_(Mg^(2+)|Mg)^(0)=-2.37V` and `E_(Fe^(3+)|Fe)^(0)=-0.04V`
The best reducing agent would be

Options

A. `Mg^(2+)`
B. `Fe^(3+)` decrease
C. `Mg`
D. `Fe`

Explanation

To determine the best reducing agent among the given options, we will analyze the standard reduction potentials provided for magnesium (Mg) and iron (Fe).

### Step-by-Step Solution:

1. **Understand Standard Reduction Potentials**:
- The standard reduction potential (E°) indicates the tendency of a species to gain electrons (be reduced). A higher E° value means a stronger oxidizing agent, while a lower E° value indicates a stronger reducing agent.

2. **Identify the Given Potentials**:
- For magnesium: \( E_{Mg^{2+}/Mg}^0 = -2.37 \, V \)
- For iron: \( E_{Fe^{3+}/Fe}^0 = -0.04 \, V \)

3. **Compare the Potentials**:
- Magnesium has a more negative standard reduction potential (-2.37 V) compared to iron (-0.04 V). This indicates that magnesium is less likely to be reduced compared to iron.

4. **Determine the Reducing Agent**:
- The species with the lower standard reduction potential is a better reducing agent because it can more readily lose electrons (be oxidized).
- Since magnesium has the lower standard reduction potential, it is the better reducing agent.

5. **Conclusion**:
- Therefore, the best reducing agent among the given options is magnesium (Mg).

### Final Answer:
The best reducing agent is **Mg**.

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