Answer:
See Bond Energy table at the bottom of this page) A H-H bond enthalpy (BE) is 436 kJ/mol, a C=C bond is 602 kJ/mol, a C-C bond is 346 kJ/mol, and a C-H BE is 413 kJ/mol. All of the changing energies for the reactants and products for this reaction are shown in the table below.
Explanation: