Nitric oxide (NO) can be formed from nitrogen, hydrogen and oxygen in two steps. In the first step, nitrogen and hydrogen react to form ammonia:
| N2(g) + 3H2(g) → 2NH3(g) |
=ΔH-92.kJ |
In the second step, ammonia and oxygen react to form nitric oxide and water:
| 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g) |
=ΔH-905.kJ |
Calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions.
Round your answer to the nearest kJ.