1. Chemical Reactions

2. Chemical Reactions At least one new substance is created
Bonds between atoms break, and/or the atoms bond in new combinations
The new substance(s) will have different physical and chemical properties than the substances that they were made from

3. Chemical Equations
A shortened way to show what happens during a chemical reaction.
The reactants are the starting substances
The products are the new substances formed from a reaction
An arrow in the middle means a change has occurred (means “yields”)
Reactants Products
Ex/ 2 H2O H2 + O2

4. Representing chemical reactions using diagrams…

5. Signs of a chemical reaction
Color change
Bubbling/Fizzing – gas production
Odor change
Energy change – gets warmer/cooler, light, sound
Precipitate - production of a solid from solution

6. Homework
Four Square Vocab Box
1. Reactant
2. Product

7. Aluminum and Copper Chloride solution
3 CuCl2 + 2 Al  2 AlCl3 + 3 Cu
Aluminum + Copper Chloride  Aluminum Chloride + Copper

8. Sodium Bicarbonate and Calcium Chloride (with water and BTB)
White granules + white powder  white powder + white crystal + clear liquid + colorless gas
Why does it turn from blue to yellow?
BTB is an INDICATOR (a chemical that changes color to indicate the presence of another chemical)
It changes from blue to yellow when carbon dioxide is present

9. Sodium Bicarbonate and Acetic Acid
NaHCO CH3COOH  NaC2H3O2 + H2O + CO2
Sodium Bicarbonate + Acetic Acid  Sodium Acetate water + carbon dioxide

10. Sodium Chloride and Water (H2O)
NaCl H2O  NaCl + H2O
salt water  salt water solution