The bond enthalpy of an O-H bond in a water molecule is approximately 463 kJ/mol. Bond enthalpy is a measure of the energy required to break a specific chemical bond, and it is an important factor in determining the stability of a molecule.In a water molecule H2O , there are two O-H bonds. The overall bond enthalpy of the molecule is the sum of the bond enthalpies of all the bonds present in the molecule. In this case, the overall bond enthalpy of the water molecule is approximately 2 x 463 kJ/mol = 926 kJ/mol.The high bond enthalpy of the O-H bond contributes to the stability of the water molecule, making it less likely to undergo chemical reactions. This high bond enthalpy also contributes to water's high boiling point 100C and high heat capacity, which are important properties for its role as a universal solvent and its involvement in various biological processes.