State what is meant by lattice energy.
Use the data in Table 1.1 to calculate the standard enthalpy change of formation, $\Delta H_f^{\circ}$, for calcium chloride. Drawing an energy cycle may help. Show your working. Hence determine $\Delta H_f^{\circ}(\text{CaCl}_2(s))$.
Three possible values for the first electron affinity of bromine are given in Table 1.2. Only one is correct. Put a tick next to the correct value. Explain your choice.
Define these terms: enthalpy change of solution; enthalpy change of hydration.
Calculate the standard enthalpy change of hydration of the chloride ion, $\text{Cl}^-(g)$. Drawing an energy cycle may help. Show your working. Hence find $\Delta H_{hyd}^{\circ}(\text{Cl}^-(g))$.
Calcium fluoride, $\text{CaF}_2(s)$, can be made directly from its elements. The value of $\Delta H_f^{\circ}(\text{CaF}_2(s))$ is $-1214\ \text{kJ mol}^{-1}$. Predict the sign of the entropy change, $\Delta S^{\circ}$, for this synthesis. Explain your answer.
Use the value of $\Delta H_f^{\circ}(\text{CaF}_2(s))$ given in (e) together with your answer to (e)(i) to predict how the feasibility of this synthesis changes as temperature increases.