Answer:
4NH₃ + 5O₂  →  4NO + 6H₂O   ΔH = -904 kj
Explanation:
Given data:
Energy evolved when one mole of NH₃ react = 226 kj
Energy evolved when 4 mole of NH₃ react =  ?
Solution:
Chemical equation:
4NH₃ + 5Oâ‚‚  →  4NO + 6Hâ‚‚O   Â
It is stated in question that when one mole of ammonia react 226 kj energy evolved.
When 4 moles react energy evolved is,
1 mol = -226 kj
4 mol × -226 kj / 1mol
-904 kj
when 4 moles of ammonia react 904 kj energy is evolved.
Complete thermal equation:
4NH₃ + 5O₂  →  4NO + 6H₂O   ΔH = -904 kj