Chapter 3, Problem 2P

Given the following reactions and their enthalpies:

$\begin{array}{l}\text{ΔH}\text{(kJ/mol)}\\ {\text{H}}_{\text{2}}\text{(g)}\to \text{2H(g)}\text{+436}\\ {\text{O}}_{\text{2}}\text{(g)}\to \text{2O(g)}+495\\ {\text{H}}_{\text{2}}\text{(g)+}\frac{1}{2}{\text{O}}_{\text{2}}\text{(g)}\to {\text{H}}_{\text{2}}\text{O(g)}\text{-242}\end{array}$

a. Devise a way to calculate $\Delta$ H for the reaction
${\text{H}}_{\text{2}}\text{O(g)}\to 2{\text{H}}_{\text{2}}\text{(g)+}{\text{O}}_{\text{2}}\text{(g)}$

b. From this, estimate the H-O bond energy.