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.