The Energy Changes of Reactions

Question 1

In reactants are bonds made or broken in a reaction?

Answer 1

Broken

Question 2

In products are bonds made or broken in a reaction?

Answer 2

Made

Question 3

Is bond breaking an exothermic or endothermic process?

Answer 3

Endothermic process

(as energy is supplied and transferred into the reaction to provide the activation energy)

BENDOMEX

Question 4

Is bond making an endothermic or exothermic process?

Answer 4

Exothermic process

(as energy is released to make the bonds)

BENDOMEX

Question 5

What is an exothermic reaction in terms of bond breaking and formation?

Answer 5

When the energy RELEASED to MAKE the bonds is GREATER than the energy SUPPLIEDand REQUIRED to BREAK the bonds

think, exo=transferred to surroundings, so energy is released

Question 6

What is an endothermic reaction in terms of bond breaking and formation?

Answer 6

When the energy REQUIREDand SUPPLIED to BREAK the bonds is GREATER than the energy RELEASED to MAKE the bonds

think, endo= transferred from surroundings, so energy is supplied!

Question 7

How do you calculate the overall energy change of a reaction?

Answer 7

1. MAKE SURE THE EQUATION IS BALANCED!!!!!
2. The sum of the breaking bond energy (+) and the making bond energy(-)

Question 8

What is BENDOMEX?

Answer 8

Breaking bonds is endothermic (as it NEEDS a supply of energy called the activation energy)

and Making bonds is exothermic (as it releases energy)