Place the following compounds in order of increasing exothermic lattice energy. Explain your answer.

$\mathrm{LiF}, \mathrm{MgO}, \mathrm{RbCl}$

The electrostatic force between two charged particles is proportional to $\frac{{\mathrm{Q}}_1\times {\mathrm{Q}}_2}{{\mathrm{r}}^2}$ where ${\mathrm{Q}}_1$ and ${\mathrm{Q}}_2$ are the charges on the particles and $\mathrm{r}$ is the distance between the centres of the particles. Use this relationship to explain why a magnesium oxide has a greater lattice energy than lithium fluoride.

The electrostatic force between two charged particles is proportional to $\frac{{\mathrm{Q}}_1\times {\mathrm{Q}}_2}{{\mathrm{r}}^2}$ where ${\mathrm{Q}}_1$ and ${\mathrm{Q}}_2$ are the charges on the particles and $\mathrm{r}$ is the distance between the centres of the particles. Use this relationship to explain why a lithium fluoride has a greater lattice energy than potassium bromide.

Which one of these equations for the calculation of the lattice energy of sodium oxide, ${\mathrm{Na}}_2\mathrm{O}$ is correct?

Explain why a cation with a smaller ionic radius has a higher charge density.

Which one of the following ions will be the best polariser of the large nitrate ion? Explain your answer.

${\mathrm{Cs}}^{+} {\mathrm{Li}}^{+} {\mathrm{Na}}^{+} {\mathrm{K}}^{+}$

Which one of these ions will be most polarised by a ${\mathrm{Mg}}^{2+}$ ion? Explain your answer.

${\mathrm{Br}}^{-} {\mathrm{Cl}}^{-} {\mathrm{F}}^{-} {\mathrm{I}}^{-}$

Write an equation to represent the enthalpy change of solution of potassium sulfate.