Chapter 6, Problem 6.85SP

Calculate a lattice energy for ${\text{CaH}}_{\text{2}}\left(s\right)$ in kilojoules per mole using the following information
$\begin{array}{l}{E}_{\text{ea}}\text{for H}\left(\text{g}\right)=-\text{72}.\text{8 kJ/mol}\\ E_{\text{i1}}\text{for Ca}\left(\text{g}\right)=+\text{589}.\text{8 kJ/mol}\\ E_{\text{i2}}\text{for Ca}\left(\text{g}\right)=+\text{1145 kJ/mol}\\ \text{Heat of sublimation for Ca}\left(\text{s}\right)=+\text{178}.\text{2 kJ/mol}\\ {\text{Bond dissociation energy for H}}_{\text{2}}\left(g\right)=+\text{435}.\text{9 kJ/mol}\\ {\text{Net energy change for the formation of CaH}}_{\text{2}}\left(s\right)\text{ from itselements}=-\text{186}.\text{2 kJ}/\text{mol}\end{array}$