Bond Enthalpies

[Alyssa Parry Disc 1H]

What are bond enthalpies and what are they used for?

[SantanaRodriguezDis1G]

it is the enthalpy change when a bond is broken. where enthalpy is the state function that allows us to keep track of energy changes at constant pressure

[Masih Tazhibi 2I]

Another important thing to note is that the bond enthalpies have a role in determining the overall Enthalpy of the reaction. If you take the summation of the enthalpies of bonds broken, and subtract from that value the summation of the enthalpies of bonds formed, you get the total enthalpy of the reaction. To find what bond enthalpies are needed, you should draw out the lewis structures of each molecule in the reaction, and figure out both the molecules that are bonded and the bond orders. Then you can do the math using the correct bond enthalpy values.