For the reaction: $2{\mathrm{H}}_{2\left(\mathrm{g}\right)} + {\mathrm{O}}_{2\left(\mathrm{g}\right)} \to 2{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{g}\right)}: ∆\mathrm{H}=-571 \mathrm{kJ}.$ Bond energy of (H-H) = 435 kJ and for (O=O) =498 kJ.Calculate the average bond energy of O-H bond using the above data is