The formation enthalpies, Δ H_f^ for H_( g ) and O_( g ) are 220.0 and 250.0 kJ mol^-1, respectively, at 298.15 K, and Δ H_f^ for H_2 O_( g ) is…

The formation enthalpies, $\displaystyle \Delta \mathrm{H}_{\mathrm{f}}{ }^{\ominus}$ for $\displaystyle \mathrm{H}_{(\mathrm{g})}$ and $\displaystyle \mathrm{O}_{(\mathrm{g})}$ are $\displaystyle 220.0$ and $\displaystyle 250.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$, respectively, at $\displaystyle 298.15$ K , and $\displaystyle \Delta \mathrm{H}_{\mathrm{f}}{ }^{\ominus}$ for $\displaystyle \mathrm{H}_2 \mathrm{O}_{(\mathrm{g})}$ is $\displaystyle -242.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$ at the same temperature. The average bond enthalpy of the $\displaystyle \mathrm{O}-\mathrm{H}$ bond in water at $\displaystyle 298.15$ K is $\displaystyle \_\_\_\_$ $\displaystyle \mathrm{kJ} \mathrm{mol}^{-1}$ (nearest integer).