C7.4 - Bond Energy Calculations (Finished) Flashcards
1
Q
What is bond energy?
A
The energy needed to break the bond between two attoms
2
Q
Why are reactions exothermic?
A
The energy released when new bonds are formed is greater than the energy needed to break the bonds in the reactants
3
Q
Why are some reactions endothermic?
A
The energy needed to break the bonds in the reactants is greater that that released when making new bonds
4
Q
What are bond energies measured in?
A
KJ/mol
5
Q
What do you need to work out to calculate the energy change in a chemical reaction?
A
1) how much energy is needed to break bonds in reactants
2) How much energy is released to form new bonds
6
Q
In summary how do you calculate bond energy (overall energy change)?
A
Energy required to break bonds - energy released by forming bonds = overall energy change
