Chapter 8, Problem 8.119QP

The lattice energy of an ionic solid such as NaCl is the enthalpy change ΔH° for the process in which the solid changes to ions. For example,

$\text{NaCl}(s)\to {\text{Na}}^{+}(g)+{\text{Cl}}^{-}(g)\Delta H=786\text{kJ/mol}$

Assume that the ionization energy and electron a affinity are ΔH values for the processes defined by those terms. The ionization energy of Na is 496 kJ/mol. Use this, the electron affinity from Table 8.4, and the lattice energy of NaCl to calculate ΔH for the following process:

$\text{Na}(g)+\text{Cl}(g)\to \text{NaCl}(s)$