Calcium nitride, $\text{Ca}_3\text{N}_2$, reacts quickly with water to give a white precipitate in alkaline solution. The oxidation number of nitrogen remains unchanged during the reaction. Write an equation for the reaction of $\text{Ca}_3\text{N}_2$ with water.
The enthalpy changes of solution, $\Delta H^\circ_{sol}$, for the hydroxides of the Group 2 elements become less endothermic down the group. State and explain the pattern in the solubilities of the Group 2 hydroxides.
Complete the energy cycle so that it shows the enthalpy changes involved in conversions between aqueous ions, gaseous ions and an ionic solid. On your diagram, label each enthalpy change with the correct symbol: lattice energy, $\Delta H^\circ_{latt}$, enthalpy change of hydration, $\Delta H^\circ_{hyd}$, or enthalpy change of solution, $\Delta H^\circ_{sol}$. Complete the three arrows so that each one points in the correct direction.
The solubility product, $K_{sp}$, for $\text{CaF}_2$ has the value $3.45 \times 10^{-11}$ at $298\,\text{K}$. Write an expression for the solubility product of $\text{CaF}_2$ and give its units.
Calculate the solubility of $\text{CaF}_2$ at $298\,\text{K}$?