Define lattice energy.
Explain why the lattice energy of $CaO$ is more exothermic than that of $LiF$.
Using the table data, estimate approximate values for the lattice energies of magnesium oxide and barium oxide. $\Delta H_{\text{latt}}\text{MgO}(s) =$ …… $\text{kJ mol}^{-1}$. $\Delta H_{\text{latt}}\text{BaO}(s) =$ …… $\text{kJ mol}^{-1}$.
Write an equation for the reaction of $\text{BaO}$ with $\text{H}_2\text{O}$. Add state symbols.
State and explain how the solubilities of the hydroxides of the Group 2 elements change down the group.
With the following data and any other relevant Data Booklet values, calculate the lattice energy of magnesium fluoride, $\text{MgF}_2\text{(s)}$. Drawing an energy cycle may help. Show your working. Data given: electron affinity of $\text{F(g)} = -348\,\text{kJ mol}^{-1}$; enthalpy change of atomisation of $\text{Mg(s)} = +147\,\text{kJ mol}^{-1}$; enthalpy change of formation of $\text{MgF}_2\text{(s)} = -1102\,\text{kJ mol}^{-1}$. Find $\Delta H_{\text{latt}}\text{MgF}_2\text{(s)}$.
Define electron affinity.
The electron affinity of carbon, $\text{C(g)}$, is $-120\,\text{kJ mol}^{-1}$. Suggest an explanation for why the electron affinity of fluorine differs from the electron affinity of carbon.