Calculate H for the following process: K(g) + Br(g) KBr(s) The lattice energy of KBr is 689

Question:

Calculate ˆ†H for the following process:
K(g) + Br(g) †’ KBr(s)
The lattice energy of KBr is 689 kJ/mol, and the ionization energy of K is 419 kJ/mol. The electron affinity of Br is given in Table 8.4. See Problem 8.109.
Problem 8.109
The lattice energy of an ionic solid such as NaCl is the enthalpy change ˆ†H° for the process in which the solid changes to ions. For example,
NaCl(s) †’ Na+(g) + Cl(g) ˆ†H = 786 kJ/mol
Assume that the ionization energy and electron affinity are ˆ†H 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 ˆ†H for the following process:
Na(g) + Cl(g) †’ NaCl(s)