Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

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