Question 243421

Calculate the ΔH for the reaction 4 NH3 (g) + 5 O2 (g) –> 4 NO (g) + 6 H20 (g), from the following data.

1) N2 (g) + O2 (g) –> 2 NO (g) ΔH= -180.5 kJ  

2) N2 (g) + 3 H2 (g) –> 2 NH3 (g) ΔH= -91.8 kJ  

3) 2 H2 (g) + O2 (g) –> 2 H2O (g) ΔH= -483.6 kJ