Question

Determine DrH° for the following reaction,
2 NH3(g) + 5/2 O2(g) ® 2 NO(g) + 3 H2O(g)
given the thermochemical equations below.
N2(g) + O2(g) ® 2 NO(g) DrH° = +180.8 kJ/mol-rxn
N2(g) + 3 H2(g) ® 2 NH3(g) DrH° = –91.8 kJ/mol-rxn
2 H2(g) + O2(g) ® 2 H2O(g) DrH° = –483.6 kJ/mol-rxn