1. Describing Chemical Reactions
(Sec 9.1 pg )

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???

8. Pg. 234 # 1,2,6,9 + Worksheet