Using data from the Data Booklet and this Born-Haber cycle, calculate the lattice energy, $\Delta H_{\text{latt}}$, for $\text{FeO(s)}$ in $\text{kJ mol}^{-1}$.
Natural iron(II) oxide is usually found as the mineral wüstite. Wüstite has the formula $\text{Fe}_2\text{O}_x$. It contains both $\text{Fe}^{2+}$ and $\text{Fe}^{3+}$ ions, with 90% of the iron present as $\text{Fe}^{2+}$ and 10% as $\text{Fe}^{3+}$. Deduce the value of $x$.
State and explain how the lattice energy of FeO(s) differs from the lattice energy of CaO(s).
Heating FeO produces $\text{Fe}_3\text{O}_4$, as shown by reaction 1: $4\text{FeO} \rightarrow \text{Fe} + \text{Fe}_3\text{O}_4$. Show how reaction 1 can be described as a disproportionation reaction.
When $\text{Fe}_3\text{O}_4(l)$ is electrolysed with inert electrodes to produce Fe, write the half-equation for the process that happens at the anode during electrolysis of $\text{Fe}_3\text{O}_4(l)$.
Calculate the greatest mass of iron metal that can be produced when $\text{Fe}_3\text{O}_4(l)$ is electrolysed for six hours at a current of $50\,\text{A}$. Assume the one $\text{Fe}^{2+}$ ion and two $\text{Fe}^{3+}$ ions are discharged at equal rates.
State one possible benefit of developing cells such as lithium-ion rechargeable batteries.
Use the cathode half-equation $\text{Li}^+ + \text{FePO}_4 + \text{e}^- \rightarrow \text{LiFePO}_4$ to identify any change in oxidation states of lithium and iron at the cathode during discharging.
Write the equation for the overall reaction that takes place as this cell discharges.