Question

Calculate the bond dissociation energy of the carbon-hydrogen bond in methane (CH4), given that the reaction CH4(g) → CH3(g) + H(g) has a ΔH° of 435 kJ/mol.

Answer 1

The bond dissociation energy of a bond is the energy required to break that bond. In this case, we are given the enthalpy change  H  for the reaction CH4 g   CH3 g  + H g , which represents the energy required to break one carbon-hydrogen bond in methane.Since the reaction involves breaking one C-H bond in methane, the bond dissociation energy of the C-H bond is equal to the H of the reaction.Bond dissociation energy of C-H bond in methane = H = 435 kJ/mol