Chapter 6, Problem 6.84SP

Born-4-Iaber cycles, such as those shown in Figures 6.7 and 6.8,are called cycles because they form dosed loops. If any five of the six energy changes ¡n the cycle are known, the value of the sixth can be calculated. Use the following five values to calculate the lattice energy in kilojoules per mole for sodium hydride, NaH(s):
$\begin{array}{l}{E}_{\text{ea}}\text{for H}\left(g\right)=-\text{72}.\text{8 kJ/mol}\\ E_{\text{i1}}\text{for Na}\left(\text{g}\right)=+\text{495}.\text{8 kJ/mol}\\ \text{Heat of sublimation for Na}\left(\text{s}\right)=+\text{1}0\text{7}.\text{3 kJ/mol}\\ {\text{Bond dissociation energy for H}}_{\text{2}}\left(\text{g}\right)=+\text{435}.\text{9 kJ/mol}\\ \text{Net energy change for the formation of NaH2}\left(\text{s}\right)\text{ from its}\text{elements}=-\text{6}0\text{ kJ/mol}\end{array}$