Calculate the heat of formation of KCl from the following data :
`{:((i),KOH(aq)+HCl(aq)rarr KCl(aq)+H_(2)O(l)",",,Delta H=-57.3 kJ mol^(-1)),((ii),H_(2)(g)+(1)/(2)O_(2)(g)rarr H_(2)O(l)",",,Delta H=-286.2 kJ mol^(-1)),((iii),(1)/(2)H_(2)(g)+(1)/(2)Cl_(2)(g)+aq rarr HCl(aq)",",,Delta H=-164.4 kJ mol^(-1)),((iv),K(s)+(1)/(2)O_(2)(g)+(1)/(2)H_(2)(g)+aq rarr KOH(aq)",",,Delta H=-487.4 kJ mol^(-1)),((v),KCl(s)+aq rarr KCl(aq)",",,Delta H=+18.4 kJ mol^(-1)):}`

Explanation

To calculate the heat of formation of KCl from the given data, we will follow a systematic approach using Hess's law. We need to arrange the provided reactions to derive the formation reaction for KCl from its elements.

### Step-by-Step Solution:

1. **Write the Target Reaction:**
We want to find the heat of formation of KCl from its elements:
\[
\text{K(s)} + \frac{1}{2}\text{Cl}_2(g) \rightarrow \text{KCl(s)}
...