Controlling Chemical Reactions Chapter 6 Section 3

Energy and Reactions Activation Energy: is the minimum amount of energy needed to start a chemical reaction. All Chemical reactions require a certain amount of activation energy to get started.

Rates of Chemical Reaction Factors that affect rates of chemical reaction include: 1. Surface Area: If you break a substance into smaller pieces more particles will be exposed and the reaction happens faster. 2. Temperature: if you increase the temperature of a substance the particles will move faster, will hit each other more often and will have more energy therefore, the reaction will happen faster.

3. Concentration: A third way to increase the rate of chemical reaction is increasing concentration. Concentrated substance has more of the particles in a given volume. 4. Catalysts: Catalysts are substances that increase the rate of chemical reaction. Example, enzymes

5. Inhibitors: Some reactions need to be slowed down, inhibitors are substances that slow down the rate of chemical reactions. Example: Food preservatives.