1. Sec 2 Rates of Chemical Reaction

2. What we’ll learn?
Determine how to describe and measure the speed of a chemical reaction.
Identify how chemical reactions can be speeded up or slowed down.

3. WHY?
Speeding up useful reactions and slowing down destructive ones can be helpful.

4. Vocabulary Words: Activation Energy Rate of Reaction Concentration
Inhibitor
Catalyst
Enzyme

5. A chemical reaction involves a collision between particles.
The particles collide and make new substances

6. Activation Energy:
The energy needed to start a reaction…

7. Reaction Rate:
The rate that tells us how fast a reaction happens after it has started.

8. Factors Affecting a Chemical Reaction:
Temperature
Concentration
Surface Area
Catalyst

9. Temperature:
Increasing temp. speeds up chemical reaction. Lowering temp. slows down a chemical reaction.

10. Surface Area:
If we make the pieces of the reactants smaller we increase the number of particles on the surface which can react.
This makes the reaction faster.
The particles on the surface can react
When cut into smaller pieces the particles on the inside can react

11. Concentration: Lower concentration-slower reaction (less collision)
There are less red particles in the same volume so there is less chance of a collision
Lower concentration-slower reaction
(less collision)
Higher concentration- fast reaction
(more collision)
There are more red particles in the same volume so there is more chance of a collision so the reaction goes faster

12. Catalyst: A substance that speeds up a chemical reaction.
Ex. Enzymes (found in the body)
-Meat Tenderizer

13. Inhibitor: A substance that slows down a chemical reaction.
Ex. BHT ( Butylated Hydroxy Toluene) found in cereals.