Type of bond Average Bond Enthalpy (kJ/mol) O-O 150O=O 500The conversion of ozone to diatomic oxygen is represented by the equation above. Based on the data in the table above, what is the approximate average bond enthalpy for the oxygen-to-oxygen bonds in ozone? a. 0 kJ/mol b. 150 kJ/mol c. 300 kJ/mol d. 500 kJ/mol

Missing information:

The reaction is 2O₃ (g) - -> 3O₂ (g) ΔH = - 300 kJ/mol

Answer:

c

Explanation:

In the molecule of ozone, 3 oxygens are bonded, and, because each one needs to share two pairs of electrons, these 2 bonds are something between a simple and a double bond.

In the reaction of the transformation of the ozone to oxygen gas, these bonds are broken, and a double bond is formed between two oxygen atoms. The sum of the energy of the broken and the formation of the bond is the enthalpy variation of the reaction.

To break a bond, energy must be added to the system, so it's an endothermic reaction and energy is positive, so the formation is exothermic and the energy is negative. Because there're 2 ozone molecules, 4 bonds will be broken, and because there are 3 oxygen molecules, 3 bonds will be formed:

4*E - 3*500 = - 300

4E = - 300 + 1500

4E = 1200

E = 300 kJ/mol

So, each O3 bond has 300 kJ/mol as an average energy.