Chapter 9, Problem 62E

Calculate $\text{ΔH}$ for the reaction

${\text{ 2NH}}_{\text{3}}\left(\text{g}\right)\text{ + }\frac{\text{1}}{\text{2}}{\text{O}}_{\text{2}}\left(\text{g}\right)\to {\text{ N}}_{\text{2}}{\text{H}}_{\text{4}}\left(\text{l}\right){\text{ + H}}_{\text{2}}\text{O}\left(\text{l}\right)$

given the following data:

${\text{2NH}}_{\text{3}}\left(\text{g}\right){\text{ + 3N}}_{\text{2}}\text{O}\left(\text{g}\right)\to \text{}{\text{ 4N}}_{\text{2}}\left(\text{g}\right){\text{ + 3H}}_{\text{2}}\text{O}\left(\text{1}\right)\text{ ΔH = —1010}\text{. kJ}$

${\text{N}}_{\text{2}}\text{O}\left(\text{g}\right){\text{ + 3H}}_{\text{2}}\left(\text{g}\right)\to {\text{ N}}_{\text{2}}{\text{H}}_{\text{4}}\left(\text{l}\right){\text{ + H}}_{\text{2}}\text{O}\left(\text{l}\right)\text{ ΔH }\text{= —317kJ}$

${\text{N}}_{\text{2}}{\text{H}}_{\text{4}}\left(\text{l}\right){\text{ + O}}_{\text{2}}\left(\text{g}\right)\to {\text{ N}}_{\text{2}}\left(\text{g}\right){\text{ + 2H}}_{\text{2}}\text{O(l) ΔH=—623kJ}$

${\text{H}}_{\text{2}}\left(\text{g}\right)\text{ + }\frac{\text{1}}{\text{2}}{\text{O}}_{\text{2}}\left(\text{g}\right)\text{}\to {\text{ H}}_{\text{2}}\text{O}\left(\text{l}\right)\text{ ΔH =}\text{—286 kJ}$