Ammonia will burn in the presence of a platinum catalyst to produce nitric oxide, NO. 4NH3(g) +

Question:

Ammonia will burn in the presence of a platinum catalyst to produce nitric oxide, NO.
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)
What is the heat of reaction at constant pressure? Use the following thermochemical equations:
N2(g) + O2(g) → 2NO(g); ∆H = –180.6 kJ
N2(g) + 3H2(g) → 2NH3(g); ∆H = –91.8 kJ
2H2(g) + O2(g) → 2H2O(g); ∆H = –483.7 kJ