1. How Can I change the speed of a Reaction?
Target 5-3

2. Target 5-3 How can I change the speed of a reaction?
What makes one reaction happen faster than another one?
What affects the speed of a reaction?

3. Reaction Rate
The reaction rate refers to how quickly the reactants transform into products
Faster rate = faster reaction

4. RECAP
Remember collision theory: In order for 2 particles to react, they must have an effective collision
They need enough kinetic energy to break bonds
They need to be reactive
They need to be in the correct orientation

5. Changing Reaction Rates
The reaction rate is dependent on the number of effective collisions
More effective collisions = faster rate

6. BRAINSTORM
To make the reaction rate faster, we need more effective collisions.
How can we make more effective collisions happen?

7. Changing Reaction Rate
Change kinetic energy (temperature)
Higher temp = more KE = more effective collisions
Lower temp = less KE = fewer effective collisions
**we can also increase KE by stirring!
Change amount of reactants
More reactants = more effective collisions
Less reactants = fewer effective collisions
**amount of reactants = CONCENTRATION**
Change form of reactants
Smaller pieces = easier to break down = more effective collisions
Ex) Powders are good, chunks are not

8. A note about CONCENTRATION
Usually, a faster rate means a shorter time for the reaction to happen.
When we increase concentration (amount of reactants), we are increasing the rate AND the amount of stuff to do
Often, this means the reaction is happening faster but also taking a longer time total

9. A Note About Concentration
Example:
A)If I am driving 70 mph and going 50 miles, it will take me 45 minutes.
B) If I am driving 35 mph and going 25 miles, it will take me 15 minutes.
Which scenario (A or B) had a shorter time?
Which scenario (A or B) had a faster rate/speed?

10. REACTION RATE STATIONS
Visit each station to explore and visualize changes in reaction rate
My expectations for your MODELS:
Models contain PARTICLES
Models contain ARROWS (why??)
I am NOT looking for an equation – I am looking for collisions!
*Hint: Put your particles in a beaker
*Hint: Draw two models for each so you can explain how we compare them (ex. low/high temp)
I need an EXPLANATION of what you drew and why you drew it that way.