The reaction;
O(g) +O2(g)→O3(g), ΔH = sum of bond enthalpy of reactants-sum of food enthalpy of products.
ΔH = ( bond enthalpy of O(g)+bond enthalpy of O2 (g) - bond enthalpy of O3(g)
-107.2 kJ/mol = O+487.7kJ/mol =O+487.7 kJ/mol +487.7kJ/mol =594.9 kJ/mol
Bond enthalpy (BE) of O3(g) is equals to 2× bond enthalpy of O3(g) because, O3(g) has two types of bonds from its lewis structure (0-0=0).
∴2BE of O3(g) = 594.9kJ/mol
Average bond enthalpy = 594.9kJ/mol/2
=297.45kJ/mol
∴ Averange bond enthalpy of O3(g) is 297.45kJ/mol.
It represents the number of moles required of that molecule to balance the chemical equation, which means to have the reaction chemically happen and goes to completion.
For example:
CH4 + O2 --> H2O + CO2 that is not balanced
with the coefficients located
CH4 + 2O2 --> 2H2O + CO2 now with the coefficients the number of oxygen and hydrogen on each side are equal
One of the atoms involved must be a metal and the other a nonmetal
FORCE is how strongly gravity pulls on an object
MASS measures how much space matter takes up
Hope that helped! Good luck!