Understanding Physical and Chemical Changes

1. Aim: How do Physical and Chemical Changes differ?Do Now: writing activityHW: handout

2. DO NOW: Writing Activity • The students will describe the three states of matter and include the following : • At least one example of each state • A description of each state

3. MATTER • Matter is everywhere. • Matter is anything that takes up space and has mass. • Matter is constantly experiencing both chemical and physical changes.

4. Physical Change • occur when matter changes its property but NOTits chemical nature. • changes could include a change in: texture, shape, size, color, odor, volume, mass, weight, and density.

5. Physical Change

6. Chemical Change • are changes matter undergoes when it becomes new or different matter. • To identify a chemical change look for signs such as color change, bubbling and fizzing, light production, smoke, and presence of heat.

7. Chemical Change • A chemical change occurs when fireworks are used. Fireworks are made of metals such as magnesium and copper. These change chemically as they light up the sky.

8. Is it a chemical or physical change? • Sugar dissolving in tea • Chemical Change • Physical Change

9. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

10. Correct!

11. Is it a chemical or physical change? • Logs burning • Chemical Change • Physical Change

12. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

13. Correct!

14. Is it a chemical or physical change? • Breaking water up by separating it into hydrogen and oxygen • Chemical Change • Physical Change

15. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

16. Correct!

17. Is it a chemical or physical change? • Cutting paper • Chemical Change • Physical Change

18. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

19. Correct!

20. Is it a chemical or physical change? • Crushing an aspirin • Chemical Change • Physical Change

21. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

22. Correct!

23. Is it a chemical or physical change? • Metal rusting • Chemical Change • Physical Change

24. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

25. Correct!

26. Is it a chemical or physical change? • Lighter fluid burining • Chemical Change • Physical Change

27. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

28. Correct!

29. Is it a chemical or physical change? • An egg rotting • Chemical Change • Physical Change

30. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

31. Correct!

32. Is it a chemical or physical change? • An egg breaking • Chemical Change • Physical Change

33. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

34. Correct!

35. Writing Activity • Write a paragraph about the difference between a chemical and physical change. Give examples of each.

36. Aim: How do we read a solubility curve? HW: HANDOUT

38. A solution is actually a type of mixture. Think of the example of salt water. This is also called a "homogenous mixture." Think of the example of sand in water. This is also called a "heterogeneous mixture." 

39. Definitions A solution is a homogeneous mixture of 2 or more substances that are uniform throughout. One constituent is usually regarded as the SOLVENT and the others as SOLUTES.

40. Parts of a Solution • SOLUTE – the part of a solution that is being dissolved (usually the lesser amount) • SOLVENT – the part of a solution that dissolves the solute (usually the greater amount) Solute + Solvent = Solution

41. Definitions Solutions can be classified as saturated or unsaturatedand super saturated A saturated solution contains the maximum quantity of solute that dissolves at that temperature. An unsaturated solution contains less than the maximum amount of solute that can dissolve at a particular temperature

42. Saturated Supersaturated Solubility curve Unsaturated

43. Solubility curve • Any point on a line represents a saturated solution. • In a saturated solution, the solvent contains the maximum amount of solute. • Example • At 90oC, 40 g of NaCl(s) in 100g H2O(l) represent a saturated solution.

44. Solubility curve • Any point below a line represents an unsaturated solution. • In an unsaturated solution, the solvent contains less than the maximum amount of solute. • Example • At 90oC, 30 g of NaCl(s) in 100g H2O(l) represent an unsaturated solution. 10 g of NaCl(s) have to be added to make the solution saturated.

45. Solubility curve • Any point above a line represents a supersaturated solution. • In a supersaturated solution, the solvent contains more than the maximum amount of solute. A supersaturated solution is very unstable and the amount in excess can precipitate or crystallize. • Example • At 90oC, 50 g of NaCl(s) in 100g H2O(l) represent a supersaturated solution. Eventually, 10 g of NaCl(s) will precipitate.

46. Solubility curve Any solution can be made saturated, unsaturated, or supersaturated by changing the temperature.