Question

Which of the following molecules has the maximum bond enthalpy?
A. `N_2(g)`
B. `CO(g)`
C. `F_2(g)`
D. `HF(g)`

Answer 1

Correct Answer - B
Both `N_2(overset(..)N-=overset(..)N)` and `CO ( : C-=O: )` have identical bond orders. However, the bond enthalpy of `CO(kJ "mol"^(-1))` is more than that of `N_2 (946 kJ "mol"^(-1))` because CO is polar while `N_2` is nonpolar. Moreover, CO exhibits resonance.