1. 2.11 Describing Chemical Reactions (Sec 9.1 pg 231-234)

2. We have learned a lot about how to classify compounds into different groups – see Fig.1 p.231.

3. A chemical reaction is any process that involves a change in the chemical properties of the compound (remember – chemical changes happen when new substances are formed; physical changes do not create new substances).

4. We can represent a chemical reaction with a chemical equation. A chemical equation uses chemical formulas to represent what happens in a reaction. The compounds you have initially are called reactants, the compounds that you end up with are called products (Fig.5 p.232).

5. Chemical reactions follow certain laws. – One of these laws is the law of conservation of mass, which states that matter is neither gained nor lost during a chemical reaction. – In other words “what goes in must come out”.

6. Chemical reactions follow certain laws. – In terms of chemical reactions, the # of atoms of each element in the reactants will equal the # of atoms of that same element in the products, but they will be re- arranged.

7. Take a look at the reaction below.....what’s wrong with this picture??? How can we fix it???