If all species are in their standard states, which of the following is the strongest oxidizing agent ?

Options

A. `Br^(-)`
B. `Zn^(2+)`
C. `CO^(3+)`
D. `Fe^(2+)`

Explanation

To determine which species is the strongest oxidizing agent among the given options when all species are in their standard states, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Oxidizing Agents**: An oxidizing agent is a substance that can accept electrons in a chemical reaction. The stronger the oxidizing agent, the more readily it will accept electrons.

2. **Standard Reduction Potentials**: Each species has a standard reduction potential (E°) value, which indicates its ability to gain electrons. A higher E° value means a stronger tendency to be reduced (and thus a stronger oxidizing agent).

3. **List the Given Species**: Identify the species provided in the question. For this example, let's assume the species are \( \text{Co}^{3+}, \text{Fe}^{2+}, \text{Zn}^{2+}, \text{Br}^- \).

4. **Find Standard Reduction Potentials**: Look up the standard reduction potentials for each species:
- \( \text{Co}^{3+} + e^- \rightarrow \text{Co}^{2+} \) (E° = +1.82 V)
- \( \text{Fe}^{2+} + 2e^- \rightarrow \text{Fe} \) (E° = +0.77 V)
- \( \text{Zn}^{2+} + 2e^- \rightarrow \text{Zn} \) (E° = -0.76 V)
- \( \text{Br}^- + e^- \rightarrow \text{Br} \) (E° = +0.07 V)

5. **Compare the Reduction Potentials**: Arrange the species in order of their standard reduction potentials:
- \( \text{Co}^{3+} \) (highest potential)
- \( \text{Fe}^{2+} \)
- \( \text{Br}^- \)
- \( \text{Zn}^{2+} \) (lowest potential)

6. **Identify the Strongest Oxidizing Agent**: The species with the highest standard reduction potential is the strongest oxidizing agent. In this case, \( \text{Co}^{3+} \) has the highest potential.

7. **Conclusion**: Therefore, the strongest oxidizing agent among the given options is \( \text{Co}^{3+} \).

### Final Answer:
The strongest oxidizing agent is \( \text{Co}^{3+} \).

---