What does the term lattice energy mean?
Write an equation to show the lattice energy of $\text{MgO}$.
The apparatus shown in the diagram may be used to determine the enthalpy change of formation of magnesium oxide, $\Delta H_f^\circ(\text{MgO})$. List the measurements you need to make with this apparatus in order to calculate $\Delta H_f^\circ(\text{MgO})$.
Use the data below, together with suitable values from the Data Booklet, to work out a value of $\Delta H_f^\circ(\text{MgO})$. lattice energy of $\text{MgO}(s)$ $= -3791\ \text{kJ mol}^{-1}$ enthalpy change of atomisation of Mg $= +148\ \text{kJ mol}^{-1}$ electron affinity of the oxygen atom $= -141\ \text{kJ mol}^{-1}$ electron affinity of the oxygen anion, $\text{O}^-$ $= +798\ \text{kJ mol}^{-1}$
Write equations, including state symbols, for the reactions, if any, of these two oxides with water. Suggest pH values for the solutions formed. $\text{Na}_2\text{O}$ $\text{MgO}$