1. Discussion: Collision Theory
Students will understand that the random movement of molecules determines how fast reactions occur.

2. Postulates What does the collision theory postulate (assume)?
All molecules are in constant random motion.
If two molecules react with each other, they must hit each other

3. Instant Questions 1. How many assumptions are there?
2. Finish this sentence,
If two molecules __(Q#2)___with each other, they must __(Q#3)___ each other.

4. Effective Collisions Not all collisions produce products.
Molecules must hit each other with sufficient force. Show video
Must hit with the proper orientation. (Must hit in the right place)

5. Instant Questions 4. Yes or NO Do all collisions cause a reaction?
They must hit with sufficient _(5)_
And they must hit with the proper _(6)_

6. Ineffective Collisions
List two ways a chemist can increase the effectiveness of collisions.
by increasing the temperature of the reaction.
By adding a catalyst.

7. Why does increasing the temperature make the reaction speed up?
As the temp is increased, the speed of the molecules increases, which makes it more likely that collisions will break bonds.

8. What is a catalyst? Watch video of a catalyst on TV
Why is this reaction so slow? N2 + 3H2  2NH3
What does the catalyst do to make the reaction speed up?

9. Draw an energy diagram of the reaction

10. Besides making the collisions more effective, what can a chemist do to increase the rate?
Increase the number of collisions by increasing the concentration of the reactants.
Watch demo with dilute acid and concentrated acid

11. Instant Question 7. A biological catalyst is called a __
8. A chemist can increase the effectiveness of collisions by increasing the temperature or by adding a ______
9. True or false: Increasing the concentration makes the collisions more effective.

12. Powder Vs Clump Oxygen reacts anywhere and everywhere
Oxygen only reacts on the surface
Oxygen reacts anywhere and everywhere

13. Video
Webertube

14. Reversible Reactions
The reaction N2 + 3H2  2NH3 is reversible. What does that mean and how is it indicated?
It means that products are also turning into reactants. We indicate it by putting a double arrow instead of a single arrow.
N2 + 3H2  2NH3

15. Fritz Haber
He was a German chemist who received the Nobel Prize in 1918 for developing a way to make ammonia.

16. The process
But you don’t have to draw this much!

17. Draw This