Calculate `Delta H` for the process at `25^(@)C` of dissolving 1.0 mol of KCI in a large excess of water..
`Delta_(f)H^(@)[K^(+)(aq)] = -251.2 kJ mol^(-1)`
`Delta_(f)H^(@)[Cl^(-)(aq)] = -167.08 kJ mol^(-1)`
`Delta_(f)H^(@)[KCl] = -437.6 kJ mol^(-1)` .

Explanation

To calculate the enthalpy change (ΔH) for the process of dissolving 1.0 mol of KCl in a large excess of water at 25°C, we can use the standard enthalpy of formation values provided for the ions and the solid KCl.

### Step-by-step Solution:

1. **Write the Dissolution Reaction:**
The dissolution of KCl in water can be represented as:
\[
\text{KCl (s)} \rightarrow \text{K}^+ \text{(aq)} + \text{Cl}^- \text{(aq)}
...