Predict and explain the pattern in enthalpy change of hydration for the ions $\text{F}^-$, $\text{Cl}^-$, $\text{Br}^-$ and $\text{I}^-$.
Fig. 2.1 shows an incomplete energy cycle for calcium fluoride, $\text{CaF}_2$. Complete line D. Include state symbols.
The enthalpy change for process 1 can be worked out from five other enthalpy changes that are not shown in Fig. 2.1. Process 1: $\text{Ca(s)} + \text{F}_2(\text{g}) \rightarrow \text{Ca}^{2+}(\text{g}) + 2\text{F}^-(\text{g})$. Identify these five other enthalpy changes, using either names or symbols.
Fig. 2.1 shows an incomplete energy cycle for calcium fluoride, $\text{CaF}_2$.
Define lattice energy, $\Delta H_{\text{latt}}$.
Complete the expression to give the mathematical relationship between $\Delta H_{\text{latt}}$ of calcium fluoride and the enthalpy changes for processes 1 and 3. $\Delta H_{\text{latt}} =$
Use data from Table 2.1 to calculate a value for the hydration energy, $\Delta H_{\text{hyd}}$, of fluoride ions, $\text{F}^-\text{(g)}$.
Define entropy.
At $298\,\text{K}$, the Gibbs free energy change, $\Delta G$, for the solution of compound T is $+6.00\,\text{kJ mol}^{-1}$. The enthalpy change of solution, $\Delta H_{\text{sol}}$, of compound T is $+30.0\,\text{kJ mol}^{-1}$ at $298\,\text{K}$. Calculate the value of the entropy change, $\Delta S$, for the solution of compound T at $298\,\text{K}$.
Predict whether compound T becomes more or less soluble as the water is heated from $298\,\text{K}$ to $360\,\text{K}$. Explain your answer.