Derive expression to calculate emf (reduction) of the following half cells at `25^@C`
`Hg_2Cl_2 (s), Cl^(-)|Hg`

Explanation

To derive the expression for the electromotive force (emf) of the half-cell reaction involving `Hg2Cl2 (s), Cl^(-)|Hg` at `25°C`, we will follow these steps:

### Step 1: Write the half-cell reaction
The half-cell reaction for the given system is:
\[ \text{Hg}_2\text{Cl}_2 (s) + 2e^- \rightarrow 2\text{Hg} (l) + 2\text{Cl}^- (aq) \]

### Step 2: Identify the number of electrons transferred
In the reaction, 2 electrons are transferred. This is important for calculating the Nernst equation.
...