Given `E_(S_(2)O_(8)^(2-)//SO_(4)^(2-)^(@)=2.05V` `E_(Br_(2)//Br^(-))^(@)=1.40V` `E_(Au^(3+)//Au)^(@)=1.10V` ,brgt `E_(O_(2)//H_(2)O)^(@)=1.20V` Which of the following is the strongest oxidizing agent ?

Options

A. `S_2O_8^(2-)`
B. `O_2`
C. `Br_2`
D. `Au^(2+)`

Explanation

To determine which of the given species is the strongest oxidizing agent, we will analyze the standard reduction potentials (E°) provided for each half-reaction. The higher the standard reduction potential, the stronger the oxidizing agent.

### Step-by-Step Solution:

1. **Identify the Standard Reduction Potentials:**
- For \( S_2O_8^{2-} + 2e^- \rightarrow 2SO_4^{2-} \), \( E° = 2.05 \, V \)
- For \( Br_2 + 2e^- \rightarrow 2Br^- \), \( E° = 1.40 \, V \)
- For \( Au^{3+} + 3e^- \rightarrow Au \), \( E° = 1.10 \, V \)
- For \( O_2 + 4H^+ + 4e^- \rightarrow 2H_2O \), \( E° = 1.20 \, V \)

2. **Compare the Standard Reduction Potentials:**
- \( E°(S_2O_8^{2-}) = 2.05 \, V \)
- \( E°(Br_2) = 1.40 \, V \)
- \( E°(Au^{3+}) = 1.10 \, V \)
- \( E°(O_2) = 1.20 \, V \)

3. **Determine the Strongest Oxidizing Agent:**
- The strongest oxidizing agent corresponds to the half-reaction with the highest standard reduction potential.
- Comparing the values:
- \( 2.05 \, V \) (for \( S_2O_8^{2-} \)) is greater than \( 1.40 \, V \), \( 1.10 \, V \), and \( 1.20 \, V \).

4. **Conclusion:**
- Since \( S_2O_8^{2-} \) has the highest standard reduction potential, it is the strongest oxidizing agent among the given options.

### Final Answer:
The strongest oxidizing agent is \( S_2O_8^{2-} \).

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