Bond energies Flashcards
1
Q
What happens during a chemical reaction?
A
Old bonds are broken and new bonds are formed.
2
Q
What type of reaction is bond breaking?
A
Endothermic
3
Q
What type of reaction is bond making?
A
Exothermic
4
Q
Energy in endothermic reactions
A
The energy needed to break bond is greater than the energy released by forming them.
5
Q
Energy in exothermic reactions
A
The energy released by forming bonds is greater than the energy used to break them.
6
Q
Enthalpy change =
A
Total energy absorbed to break bonds - total energy released in making bonds
7
Q
How to do bond energy calculations
A
1) Work out the energy required to break the original bonds in the reactants.
2) Work out the energy released by forming the new bonds in the products .
3) Work out the enthalpy change.
