1. Review

2. LIQUID
SOLID
GAS

3. Vaporization? Deposition? Freezing? Condensation? Sublimation?
Adding Energy
Removing Energy
Melting?
Vaporization?
Deposition?
Freezing?
Condensation?
Sublimation?

4. Chemical Change
One or more substances changing into new substances with new compositions and properties

5. Examples:
Baking a cake

6. Examples:
rust
Iron-oxide

7. Chemical Changes Starting substances - reactants
New substance - product
Reactants Product

8. Evidence of a chemical change
Always a change in properties

9. Evidence of a chemical change
Color – statue of liberty

10. Evidence of a chemical change
Odor – sour milk

11. Evidence of a chemical change
Produce heat / light - sparkler

12. Heat reactions
Exothermic reaction – gives off heat
Endothermic reaction – takes in heat

13. Evidence of a chemical change
Produce gas – antacid tablets

14. Evidence of a chemical change
Produce solid – precipitate
Lead(II) Nitrate Sodium Iodide

15. Physical vs. Chemical Change
when matter undergoes physical change, its shape or form changes, but its identity remains the same. When matter undergoes a chemical change, its identity and properties change.

16. Can reverse – Physical Change
After ice melts into liquid water, you can refreeze it into solid ice if the temperature drops.  Freezing and melting are physical changes.

17. Can’t reverse - Chemical Change
As wood burns, it turns into a pile of ashes and gases that rise into air.  After the wood is burned, it cannot be restored to its original form as a log.

18. Physical or Chemical Change?

19. Physical or Chemical Change?

20. Physical or Chemical Change?

21. Physical or Chemical Change?

22. Physical or Chemical Change?

23. Physical or Chemical Change?

24. Physical or Chemical Change?

25. Physical or Chemical Change?

26. Physical or Chemical Change?
Rotten Egg

27. Physical or Chemical Change?

28. Physical or Chemical Change?

29. Physical or Chemical Change?

30. Physical or Chemical Change?

31. Measuring Chemical Reactions
By measuring mass before and after chemical reactions, it was observed that, although chemical changes occurred, the total mass involved in the reaction remained constant.

32. Law of Conservation of Mass
Mass is neither created nor destroyed during a chemical reaction – it is conserved
Mass of reactants = mass of product

33. Mercury Oxide
1774 Lavoisier

34. Mercury Oxide
10.00 g of mercury oxide is heated until it becomes liquid mercury and oxygen gas. The liquid mercury has a mass of 9.26 g. What is the mass of the oxygen?

35. DEMO
Baking soda
Vinegar
Balance
Balloon
Container

36. Practice
In the complete reaction of g of sodium with g of chlorine, what mass of sodium chloride is formed? =

37. Practice
A 12.2 g sample of X reacts with a sample of Y to form 78.9 g of sample XY. What is the mass of Y that reacted?