Bond Enthalpies

[Emily Orozco L4]

How do we use bond enthalpies to calculate change of enthalpy?

[Tracy Tolentino_2E]

Bond enthalpies can be used to calculate the net enthalpy change.
For the reactants, bond energies are positive because it takes energy for bonds to break. For products, energy is negative because when bonds form, energy is released. We then add all the energy values to gain the net enthalpy change.

[Brianna Becerra 1B]

The specific bond enthalpy values to use in calculating the net change is either given or can be found on a table by locating the specific bond formation or breakage and taking this number and applying it as a positive for reactants and a positive for reactants and then adding them all together.

[Alex Tchekanov Dis 2k]

You can look at it as the sum of Bonds Broken - the sum of Bonds Formed
This will get you the delta H value.