Bond Enthalpy

Question 1

How can enthalpy be worked out with bonds broken/ made in a reaction

Answer 1

The difference in energy released when bonds are made and energy released when bonds are made

Question 2

Breaking bonds is…

Answer 2

Endothermic because energy is taken IN to break bonds
So energy change of atoms is positive

Question 3

Making bonds is…

Answer 3

Exothermic because energy is released when bonds are formed
So energy change of atoms is negative

Question 4

If more energy is released (through bonds made) than energy taken in (through bonds broken)

Answer 4

Then the reaction is exothermic and the energy change is negative (energy released is more)

Question 5

If more energy is taken in (through bonds being broken) than energy released (through bonds being made)

Answer 5

Then the reaction is endothermic and the energy change is positive (energy taken in more)

Question 6

Bond enthalpy

Answer 6

The amount of energy required to break 1 mole of a type of bond (eg ionic or covalent) in a molecule in the gas phase

Question 7

If breaking bonds takes in energy then bond Enthalpy pues are always…

Answer 7

Endothermic processes
Takes in energy into molecule so the value is POSITIVE

Question 8

stronger bonds have…

Answer 8

Higher bond Enthalpies as more energy is required to break the bond

Question 9

Weaker bonds have…

Answer 9

Lower bond enthalpies as less energy is required to break the bond