Complete the electrons in boxes diagram in Fig. 1.1 so that it shows the electronic configuration of a zinc(II) ion.
Complete Fig. 1.2 so that it shows the Born-Haber diagram for the ionic solid ZnS. Add the state symbols for the relevant species.
Describe the trend in the first electron affinity of the Group 16 elements S to Te. Explain your answer.
Explain why the lattice energy, $\Delta H_{\text{latt}}$, of ZnO is more exothermic than that of ZnS.
Zinc metal may be produced by a two-step process shown below. Step 1: $\text{2ZnS(s)} + \text{3O}_2\text{(g)} \rightarrow \text{2ZnO(s)} + \text{2SO}_2\text{(g)}$ Step 2: $\text{ZnO(s)} + \text{C(s)} \rightarrow \text{Zn(l)} + \text{CO(g)}$ These reactions are performed at $800\,^{\circ}\text{C}$. Predict the sign of the entropy change, $\Delta S^{\circ}$, for the reaction in step 1. Explain your answer.
Use the data in Table 1.1 to calculate $\Delta S^{\circ}$ for the reaction shown in step 2.
An equation for the direct reduction of ZnS by carbon is given. $\text{2ZnS(s)} + \text{C(s)} \rightarrow \text{2Zn(l)} + \text{CS}_2\text{(g)}$ $\Delta H^{\circ} = +733\,\text{kJ mol}^{-1}$, $\Delta S^{\circ} = +218\,\text{J K}^{-1}\text{ mol}^{-1}$. This reaction is not feasible at $800\,^{\circ}\text{C}$. Calculate $\Delta G^{\circ}$ for this reaction at $800\,^{\circ}\text{C}$.
When heated, $Zn(NO_3)_2$ undergoes thermal decomposition. This behaves like the thermal decomposition of Group 2 nitrates. Write an equation for the thermal decomposition of $Zn(NO_3)_2$.
Table 1.2 shows the radii of some Group 2 cations and $\text{Zn}^{2+}$. State and explain the trend in thermal stability of the Group 2 nitrates down the group.
Use Table 1.2 to suggest which Group 2 nitrates are less thermally stable than zinc nitrate.