Balancing reactions and different types of reactions

1. Chemical Reactions Chapter 11

2. Using Everyday Equations Every minute of the day chemical reactions are taking place both in and around you. What makes something a chemical reaction? A chemical reaction involves one or more substances, the reactants, changing into one or more substances, the products. Reactants Products “ ” means “yields” or “reacts to produce.”

3. Chemical reactions can be described many ways. One is by using a word equation. A word equation is an equation where reactants and products are represented by words. Example: methane + oxygen Word equations, while useful, are cumbersome. To better describe a reaction, writing the formulas is used. A chemical equation uses formulas of reactants (on the left) separated by an arrow from products (on the right). carbon dioxide + water

4. Example: Fe + O 2 (Skeleton equation) - does not indicate the relative amounts of reactants and products Most often symbols are used to describe the state (i.e., gas, solid, etc.) of each substance Fe 2 O 3

8. Try to balance this reaction: __Al(OH) 3 (s) + __H 2 SO 4 (aq)  __Al 2 (SO 4 ) 3 (aq) + __H 2 O(l) Al S H O Al S H O 1 1 5 7 2 3 2 13 12 18 8 2 3 6 2 10 3 12 18