Derive expression to calculate emf (reduction) of the following half cells at `25^@C`
`Fe^(3+)|Fe^(2+) (Pt)`

Explanation

To derive the expression for the electromotive force (emf) of the half-cell reaction \( \text{Fe}^{3+} + e^- \rightarrow \text{Fe}^{2+} \) at \( 25^\circ C \), we will follow these steps:

### Step 1: Identify the half-cell reaction
The half-cell reaction involves the reduction of ferric ions (\( \text{Fe}^{3+} \)) to ferrous ions (\( \text{Fe}^{2+} \)). The balanced half-cell reaction can be written as:
\[ \text{Fe}^{3+} + e^- \rightarrow \text{Fe}^{2+} \]

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