Chapter 9, Problem 76E

The reusable booster rockets of the space shuttle use a mixture of aluminum and ammonium perchlorate as fuel. A possible reaction is

$\text{3Al(s)}\text{+}{\text{ 3NH}}_{\text{4}}{\text{ClO}}_{\text{4}}\text{(s)}\to {\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\text{(s)}\text{ +}\text{}\text{}{\text{AlCl}}_{\text{3}}\text{(s)}\text{+}\text{3NO(g)}\text{+}{\text{6H}}_{\text{2}}\text{O(g)}$

Calculate $\text{ΔH°}$ for this reaction.