1. Chapter 2: Common Reactions in Our Lives Unit A: Matter and Chemical Change

2. 2.1 Useful Reactions  During a chemical reaction, substance react to produce new substances with different properties from the original substances.  What are some examples of chemical reactions?

3. 2.2 The Changes That Occur  Some chemical reactions require energy, while some produce energy.  The substances you start with are not the same as the substances you end up with..  There are several indicators that may occur after some chemical reactions.  One sign is the release or absorption of energy ProductsReactants

4. 2.2 The Changes That Occur  Combustion Reaction  Neutralization Reaction Magnesium hydroxide reacts with hydrochloric acid to produce magnesium chloride. Neutralization Reaction

5. 2.3 Evidence That Change Has Occurred  A different color is produced  An odour can be detected  Bubbles appear or a gas forms  A solid that forms during a chemical readtion is called a precipitate  Energy is given off in some form or absorbed  Light  Heat  Sound

6. 2.4 Energy and Chemical Reactions  An energy change is an obvious or unnoticeable production or absorption of a form of energy as a part of a chemical change.  An endothermic reaction is any chemical reaction that absorbs heat.  An exothermic reaction is any chemical reaction that releases heat