Electrode potential data are given below:
`Fe^(3+)(aq)+e^(-)rarrFe^(2+)(aq):E^(@)=+0.77V`
`Al^(3+)+3e^(-)rarrAl(s):E^(@)=-1.66V`
`Br_(2)(aq)+2e^(-)rarr2Br^(-)(aq):E^(@)=+1.08V`,
Based on the data, the reducing power of `Fe^(2+)` Al and `Br^(-)` will increase in the order

Options

A. `Br^(-)ltFe^(2+)ltAl`
B. `Fe^(2+)ltAlltBr^(-)`
C. `AlltBr^(-)ltFe^(2+)`
D. `AlltFe^(2+)ltltBr^(-)`

Explanation

To determine the reducing power of \( \text{Fe}^{2+} \), \( \text{Al} \), and \( \text{Br}^- \) based on the provided electrode potential data, we need to follow these steps:

### Step 1: Understand the Concept of Reducing Power
Reducing power refers to the ability of a species to donate electrons and reduce another species. A higher oxidation potential indicates a stronger reducing agent.

### Step 2: Identify the Reduction Potentials
The given reduction potentials are:
- \( \text{Fe}^{3+} + e^- \rightarrow \text{Fe}^{2+} \): \( E^\circ = +0.77 \, \text{V} \)
- \( \text{Al}^{3+} + 3e^- \rightarrow \text{Al}(s) \): \( E^\circ = -1.66 \, \text{V} \)
- \( \text{Br}_2 + 2e^- \rightarrow 2\text{Br}^- \): \( E^\circ = +1.08 \, \text{V} \)

### Step 3: Calculate the Oxidation Potentials
To find the reducing power, we need to convert the reduction potentials to oxidation potentials. The oxidation potential is the negative of the reduction potential:
- For \( \text{Fe}^{2+} \):
\[ E^\circ_{\text{oxidation}} = -E^\circ_{\text{reduction}} = -0.77 \, \text{V} \]
- For \( \text{Al} \):
\[ E^\circ_{\text{oxidation}} = -(-1.66 \, \text{V}) = +1.66 \, \text{V} \]
- For \( \text{Br}^- \):
\[ E^\circ_{\text{oxidation}} = -(+1.08 \, \text{V}) = -1.08 \, \text{V} \]

### Step 4: Compare the Oxidation Potentials
Now we compare the oxidation potentials:
- \( \text{Fe}^{2+} \): \( -0.77 \, \text{V} \)
- \( \text{Al} \): \( +1.66 \, \text{V} \)
- \( \text{Br}^- \): \( -1.08 \, \text{V} \)

### Step 5: Determine the Order of Reducing Power
The reducing power increases with the increase in oxidation potential. Therefore, the order of reducing power from weakest to strongest is:
1. \( \text{Br}^- \) (oxidation potential: -1.08 V)
2. \( \text{Fe}^{2+} \) (oxidation potential: -0.77 V)
3. \( \text{Al} \) (oxidation potential: +1.66 V)

### Final Answer
The reducing power of \( \text{Fe}^{2+} \), \( \text{Al} \), and \( \text{Br}^- \) will increase in the order:
\[ \text{Br}^- < \text{Fe}^{2+} < \text{Al} \]