If ΔH0f of N2O = 82 kJ mol-1
Bond energy of N ≡ N, N = N, O = O and N = O bonds is 946, 148, 498 and 607 kJ mol-1 respectively.
Then the resonance energy of N2O will be
(A) 88 kJ mol-1
(B) 178 kJ mol-1
(C) 252 kJ mol-1
(D) 36 kJ mol-1
Explanation
= 946 + 249 - 607 - 418
= 1195 - 1025 = 170 kJ mol-1
Resonance energy = Observed heat of formation – calculated heat of formation
= 82 -170 = 88 kJ mol-1
