Bonddissociation energy is defined as energy needed to break up aspecific bond i
ID: 684791 • Letter: B
Question
Bonddissociation energy is defined as energy needed to break up aspecific
bond in amolecule. We can also consider it to be an enthalpy of the bondbreaking
reaction.Using this reasoning and BDE of molecular oxygen(O2)estimate the
enthalpy offormation of O radical (Hf O). BDE of O2 is495 kJ/mol. Write a
balancedchemical equation first and show schematically all enthalpies offormation
Explanation / Answer
O2 => 2 O* delH_rxn = bonds broken - bonds formed = 495 kJ - 0 delH_rxn = 2*delH_O*_formation formation reaction: 0.5 O2 => O* delH_O*_formation = 495 kJ/2 = 247.5 kJ/mol