Reactants, products, catalysts

1. Chemical Reactions

2. A balanced equation Notice that both sides of the arrow have the same numbers of elements

3. Law of Conservation of Mass in a chemical reaction, the total mass of the reactants is the same as the total mass of the products Antoine Laurent Lavoisier 1743-1794

4. Law of Constant proportions in chemical compounds, the ratio of the elements is always the same Joseph Proust 1754-1826

5. Reactant Reactants are any chemicals that you start with. Reactants and Products Product Products are the chemicals that are made in the reaction.

6. In our example: Hydrogen and Oxygen are the reactants Water is the product

7. While some reactions happen spontaneously when reactants are mixed, others will require a catalyst.

8. An example of a catalyst is the application of heat to the reactants. The catalyst is written over the top of the arrow in the equation as drawn below: