2. Law of Conservation of Mass  Matter cannot be created nor destroyed during a physical or chemical change.  The sum of the reactants will equal the sum of the products after a physical or chemical change.  Reactants  Products: Matter is conserved.  Antoine Lavosier

3. Aluminum and Copper Chloride  2Al + 3CuCl 2  3Cu + 2AlCl 3  Two AluminumTwo Aluminum  Three CopperThree Copper  Six ChlorineSix Chlorine  Reactants EQUAL Products

4. Copper Chloride and Sodium Hydrogen Phosphate  3CuCl 2 + 2Na 3 PO 4 ---> Cu 3 (PO 4 ) 2 + 6NaCl  3 Copper3 Copper  6 Chlorine6 Chlorine  6 Sodium6 Sodium  2 Phosphorus2 Phosphorus  8 Oxygen8 Oxygen

5. Chemical vs. Physical  Chemical Change : reactants mix together to form a new product with different properties  Gas is formed  Rust is formed  Precipitate (solid) formed  Physical Change : reactants mix together but product maintains the same properties as the reactants.  Melting  Freezing  Dissolving

6. Chemical vs. Physical  Which experiments demonstrated a chemical change?  Which experiments demonstrated a physical change?