AIIMS2010ChemistryThermodynamics (C)
Assertion : Bond energy and bond dissociation energy have identical value for diatomic molecules. Reason : Greater the bond dissociation energy, less reactive is the bond.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion
- BIf both assertion and reason are true but reason is not the correct explanation of assertion
- CIf assertion is true but reason is false
- DIf both assertion and reason are false.
Correct answer
B. If both assertion and reason are true but reason is not the correct explanation of assertion
Step-by-step solution
Bond dissociation energy is the energy required to break a particular bond in one mole of a gaseous molecule. Bond energy is the average values of dissociation energies of the same type of bond present in the molecule. Bond energy of C - H bond in methane is 99.2 kcal / mol . Thus for polyatomic molecules, average bond energy is taken as the dissociation bond energy.