In chemical reactions, heat is converted into chemical energy (the potential energy stored in chemical bonds) or vice versa. Thus, enthalpy change for a reaction can be approximated from:
/ΔH/circ = D/rm(reactants) - D/rm(products)
where "D" represents bond dissociation energies of the reactants and products, respectively. The table below contains the bond dissociation energies for common bonds. The information can be used to calculate the energy needed to break all the bonds in a given molecule.
a) Calculate the bond dissociation energy for the breaking of all the bonds in a mole of methane, CH4.
b) What is the bond dissociation energy for breaking all the bonds in a mole of O 2 molecules?
c) Calculate the bond dissociation energy needed to break all the bonds in a mole of carbon dioxide,CO2.
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Bond Energy concept. If you need more Bond Energy practice, you can also practice Bond Energy practice problems.