Chapter 9, Problem 9.135CP

Find $\Delta H°$ in kilojoules for the reaction of nitric oxide with oxygen,

$\text{2NO(g)}+{\text{O}}_2(g)\to {\text{N}}_{\text{2}}{\text{O}}_{\text{4}}\text{(g)}$ , given the following data:

${\text{N}}_{\text{2}}{\text{O}}_{\text{4}}\text{(g)}\to \text{2}N{O}_2(g)$ $\Delta H°$ = 553kJ

$\text{NO(g)}+\text{l}/{\text{2O}}_{\text{2}}\text{(g)}\to {\text{NO}}_{\text{2}}\text{(g)}$ $\Delta H°$= -58.1 kJ