Potassium chloride
= Potassium chloride
{title2=$\mathrm{KCl}$}
{wiki}
<Potassium chloride> is $\mathrm{KCl}$, a one-to-one ionic compound of potassium and chloride. Its solid lattice and the hydration of its dissolved ions contribute opposing terms to its enthalpy of solution.
Dissolution calorimetry therefore probes the whole transformation from a specified solid to a specified solution state. The observed heat is not simply a direct measurement of the energy of one potassium-chloride pair.