1. Section 1: Reaction Rate
Unit 7: Reaction Energy
Section 1: Reaction Rate

2. Energy in Reactions
In order for a reaction to occur, energy MUST be involved.
Reactions that release (give off) energy are called exothermic reactions
Reactions that absorb (take in) energy are called endothermic reactions
This energy absorbed or released is beyond the activation energy – energy required to cause a reaction to occur

3. Reaction Rate
The rate at which reactants change into products over time
Relates to how fast the reaction is occurring

4. Factors Affecting Reaction Rate
Temperature:
Generally, as you increase temperature, you increase the rate of the reaction
As you heat a substance, the molecules move around faster
They collide and react more!

5. Factors Affecting Reaction Rate
Surface Area:
The surface of a substance is the area that will react with its surroundings
An increase in the surface area results in an increase in the amount of exposure the substance has to the surroundings
Increased surface area increases reaction rate

6. Factors Affecting Reaction Rate
Concentration:
Refers to the number of particles of a substance in a given area
The more particles present, the higher the concentration and therefore, the quicker a reaction will occur

7. Factors Affecting Reaction Rate
Temperature
Increase in Reaction Rate
Surface Area
Concentration

8. Factors Affecting Reaction Rate
Catalysts:
Substance that affects the reaction rate without being used up in the process
Instead of affecting the particles that are reacting, a catalyst DECREASES the activation energy of a reaction; therefore, making the reaction occur more easily!