The bond enthalpy in NO is 632 kJ/mol and that of each NO bond in NO2 is 469 kJ/mol. Explain the difference in bond enthalpies between the two molecules.
1. NO has a double bond while in NO2 the bonds are equivalent due to resonance.
2. NO has a single bond while in NO2 the bonds are equivalent due to resonance.
3. Double bonds always have a larger bond enthalpy than single bonds.
4. The bond type does not explain the dif- ference.
