Calculating the Bond Energy 1. The average bond energy is therefore 16624 kJ which is 4155 kJ per mole of bonds. Therefore by comparing the bond energies of the bonds broken in the reactants and the bond energies of the bonds formed in the products we can calculate the enthalpy change of the reaction.
Mean bond enthalpies are sometimes referred to as bond enthalpy terms.
That means that many bond enthalpies are actually quoted as mean or average bond enthalpies although it might not actually say so. Multiply the bond energies by the number of bonds broken. Add up all of the bond. For example the bond enthalpy of the oxygen-hydrogen single bond is equal to 463 kJmol.