Chapter 2: Common Reactions in Our Lives

Unit A: Matter and Chemical Change

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?

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

2.2 The Changes That Occur Combustion Reaction

Neutralization Reaction

Magnesium hydroxide reacts with hydrochloric acid to produce magnesium chloride. Neutralization Reaction

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

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