1. Reaction Rates and Collision Theory
“Ours is an increasingly raucous visual culture and it’s important that we as viewers don’t blunt our critical abilities. We need to continue to question images and not just consume them passively within the constrictions of received proscribed norms of how images should be read.
In my case this has acted as a powerful creative catalyst leading me to experiment with creating new visual perspectives.”
Thomas Robson: “Decon 2”

3. Rate of Reaction the speed at which a chemical reaction occurs.
Some reactions are quick
Some are not
The rate of a reaction can be altered

4. Measuring rate of reaction
Two common ways:
Measure how fast the products are formed
Colour change
Gas formation
Measure how fast the reactants are used up

5. Slows down as time passes as reactants are used up
Rate of reaction graph
Amount of product formed
Slows down as time passes as reactants are used up
Reaction begins rapidly
Stops after a certain time – graph levels out as one (or both) reactants have been used up.
Time

6. Collision Theory
“For a reaction between two particles to occur, the particles must collide and the collision must be effective”

7. Effective Collisions
When the particles collide with enough kinetic energy and the correct orientation to break the bonds between particles so new bonds can form.
Collisions can occur and yet result in no reaction if there is insufficient energy or incorrect orientation.

8. Not enough energy – no reaction
How do reactions occur?
Reactions take place when particles collide with a certain amount of energy.
Not enough energy – no reaction

9. Incorrect orientation – no reaction
How do reactions occur?
Reactions take place when particles collide with a certain amount of energy.
Incorrect orientation – no reaction

10. Enough energy and correct orientation –reaction!
How do reactions occur?
Reactions take place when particles collide with a certain amount of energy.
Enough energy and correct orientation –reaction!

11. Boardworks GCSE Additional Science: Chemistry Rates of Reaction
Activation Energy
The minimum amount of energy needed for the particles to react is called the activation energy, and is different for each reaction.
If particles collide with less energy than the activation energy, they will not react.
Kick-starting Reactions - Activation Energy

12. How to speed up chemical reactions (and get a date).
Collisions and Rate
The more frequently effective collisions occur the faster the rate of reaction.
Change the concentration of reactants
Change the temperature of the reaction
Change the surface area of reactants
Use a catalyst
To change the rate of reaction we can:
How to speed up chemical reactions (and get a date).

13. Concentration
Increasing the concentration of a reactant increases the number of particles per volume . This increases the frequency of collisions. Which increases the rate of the reaction

14. Surface Area
Increasing the surface area of a reactant increases the number of particles available to react. This increases the frequency of collisions which increases the rate of the reaction.

15. Temperature
Increasing the temperature of a reaction increases the kinetic energy of the particles. The particles collide more often and with more energy this increases the frequency of effective collisions which increases the rate of reaction

16. In Summary SLOW REACTIONS FAST REACTIONS Low Temp High Temp
Low Concentration
High Concentration
Small Surface Area
Large Surface Area