(a(i))[1]
Define the enthalpy change of hydration.
(a(ii))[2]
Explain why the enthalpy changes of hydration of $\text{K}^+$ and $\text{Ca}^{2+}$ are different in magnitude.
(a(iii))[1]
Define the lattice energy.
(a(iv))[2]
The lattice energy, $\Delta H_{latt}$, of calcium fluoride, $\text{CaF}_2$, is $-2602\,\text{kJ mol}^{-1}$. Calculate the enthalpy change of solution, $\Delta H_{sol}$, in $\text{kJ mol}^{-1}$, for $\text{CaF}_2$.
(b)[2]
The formation of $\text{CaF}_2$ at $298\,\text{K}$ is represented here. $\text{Ca}(s) + \text{F}_2(g) \rightarrow \text{CaF}_2(s)$. $\Delta H^\circ = -1214\,\text{kJ mol}^{-1}$ and $\Delta G^\circ = -1162\,\text{kJ mol}^{-1}$. Calculate the entropy change, $\Delta S^\circ$, in $\text{J K}^{-1}\text{ mol}^{-1}$, for this reaction.