1. Controlling Chemical Reaction Lesson 10

2. Chemical Reaction Add vocab words to vocab sections
Diet Coke and Mentos
Add vocab words to vocab sections
Activation Energy: minimum amount of energy to start chemical reaction
Concentration: amount of substance in a given volume
Catalysts: material that increases the rate of reaction by lowering activation energy
Enzyme: a catalyst that provides a surface for a reaction to take place
Inhibitor: material used to decrease the rate of a reaction

3. Energy and Reactions Activation Energy
Reactions won’t occur until they have enough energy
Energy is used to break the bonds of the reactants  then the atoms begin to form new chemical bonds of the products
Activation energy: minimum amount of energy needed to start a chemical reaction
All chemical reactions need a certain amount of energy to get started
Think about waking up for the day. You have lots of things to get done but need to muster the energy to get out of bed and start you day  chemical reactions need energy to start

4. Exothermic and Endothermic
Exothermic Reaction
Products have less energy that reactants after the reaction
This difference is a result in a loss of heat
Ex. Burning wood, gas, oil

5. Fill in the blank
In an exothermic reaction, the ____________ have less energy than the ___________
The difference is a result from loss of _____________
An example of a exothermic reaction is ____________________
Products, result, heat, burning wood, gas, oil

6. Exothermic and Endothermic
Endothermic Reactions
Products have more energy than the reactants
The reactions must continue to absorb energy to continue
Heat absorption
Ex. Baking bread, photosynthesis (chlorophyll is used to react CO2 plus H2O plus energy to make glucose and oxygen)

7. Fill in the Blank
In Endothermic Reactions _____________ have ___________ energy than the reactants
The reactions must continue to absorb __________ to continue
Examples include _______________

8. Rates of Chemical Reactions
Do not occur all at the same rate
Chemist can change the rate of reaction by changing
Surface area
Temperature
Concentration
Using catalyst and inhibitors
Explosion very fast , rusting metal very slow

9. Temperature Heating a substance causes particles to move faster
Fast particles increase the reaction in one of two ways
1. coming into contact more often  more chances for a reaction to occur
2. faster particles have more energy  helps reactants get over the “hump” of the activation energy
Reducing temperature slows down reactions

10. Fill in the blank
Heating a substance causes particles to move ___________
Fast particles _____________ the reaction
Reducing _________________ slows down the reaction

11. Concentration Increase the concentration = increase rate of reaction
Ex. Adding a small spoonful of sugar to a glass of lemonade will make it but adding a large spoonful of sugar will make it even more sweet. The glass with more sugar has a high concentration of sugar
Increasing concentration of reactants supplies more particles to react, therefore increasing the rate of reaction

12. Fill in the blank
Increasing the concentration will increase the ________________
Increasing __________________ of reactants supplies more particles to react
Rate of the reaction, concentration

13. Catalyst and Inhibitors
Catalyst increases the rate of a reaction by lowering the activation energy
Enzymes are catalyst that provide a surface for reactions to take place
Very specific, each one affects only ONE chemical reaction
Inhibitor: prevent reactants from coming together
Slows down reactions
Found in preservatives added to food