Chapter 6, Problem 6.83SP

Look up the lattice energies in Table 6.3, and calculate the energy change in kilojoules per mole for the formation of the following substances from their elements.
(a) LiF(s) (The sublimation energy for Li(s) is +159.4 kJ/mol, the $E_{\text{i}}$ for Li(g) is 520 kJ/mol, the $E_{\text{ea}}$ for F(g) is $-\text{328 kJ/mol}$ , and the bond dissociation energy of ${\text{F}}_{\text{2}}\left(g\right)$ is $+\text{158 kJ/mol}$ .]
(b) CaF₂(s) [The sublimation energy for Ca(s) is + 178.2 kJ/mol, ${\text{E}}_{\text{i1}}=+\text{589}.\text{8 kJ/mol}$ , and $E_{\text{i2}}=+\text{1145 kJ/mol}$ .]