1. 3.6.1 Energy During Collision
3.6 Activation Energy
3.6.1 Energy During Collision
LO: I understand how the chemical energy of a reaction mixture changes during the reaction.

2. collide break form A activated complex
In order to react:
collide
the reactant molecules must
break
the bonds in the reactants must
form
the bonds in the products must A
The intermediate (A) is highly unstable and is known as an
activated complex
LO: I understand how the chemical energy of a reaction mixture changes during the reaction.

3. The progress can be shown using a potential energy diagram:
LO: I understand how the chemical energy of a reaction mixture changes during the reaction.

4. 3.6.2 Potential Energy Diagrams
LO: I understand what is meant by the activation energy.

5. The activation energy (Ea) is the additional energy needed by the reactant molecules to form the .
activated complex
activated complex PE Ea
reactant PE
Activation energy = =
30 kJ mol-1
LO: I understand what is meant by the activation energy.

6. Ea =
80 kJ mol-1
Ea =
200 kJ mol-1
LO: I understand what is meant by the activation energy.

7. 3.6.3 The Catalytic Effect
LO: I understand the effect a catalyst has on the activation energy.

8. The catalyst , the activation energy.
From the diagram:
The catalyst makes no difference to the PE of the reactants or products.
lowers
The catalyst , the activation energy.
less
Using a catalyst, energy is needed to form an activated complex.
LO: I understand the effect a catalyst has on the activation energy.