Physical/Chemical Changes

1. Physical/Chemical Changes

2. Admit Slip • Which of the following is a homogeneous mixture and why? A. Water H2O B. Tomato juice C. A turkey sandwich D. Table salt, NaCl

3. Today’s Objectives: • Students will be able to: • Define, compare and contrast mixtures, heterogeneous mixtures, homogeneous mixtures, phases, elements, compounds, and pure substances • Define and compare physical and chemical changes

4. Agenda • Homework Check/Review • Notes • Questions in our Notes • Exit Slip Product: Notes and Questions Homework: Reading and questions from book

5. Homework due Thursday College Prep Chemistry (Double HW) • Read pages 357 – 364 in your Chemistry book • And Answer the following questions; • Pg. 359 # 1 • Pg. 360 #5 • Pg. 364 # 1, 3, 4, 7

6. Homework due Thursday Honors Chemistry (Triple HW) • Read pages 41-42, 44-47, and 48- 51, and 53-55 in your Chemistry book • And Answer the following questions; • Pg. 42 #3, 4 • Pg. 47 #11, 14, 16 • Pg. 52 # 20, 24, 27 • Pg. 55 # 28 – 34

7. Homework Review 1. What are the two types of mixtures? 2. How are mixtures separated: by a chemical or physical process? 3. Name a few of these methods used to separate mixtures

8. Homework Review • Give an example of each type of mixture. • Which of these is not a mixture?A. oil and water B. sand and water C. diet soda D. all are mixtures

9. Physical and Chemical Changes 2/5/13 • During a physical change, some properties of a material change but the composition (makeup) does not change. • Physical changes include boiling, freezing, melting, condensing, breaking, filtering, evaporating, distilling, cutting, separating, dissolving, and mixing. • Physical changes may change the physical form or state of matter but do not change its composition.

10. During a chemical change, the composition of the matter always changes. A chemical change is also known as a chemical reaction. • Words that indicate chemical changes are “reacts, burn, rot, rust, decompose, ferment, explode, and corrode”

11. Notes • In a chemical reaction, the substance at the beginning is called a reactant and the end result is a product. In a chemical reaction, the products will be different from the reactants. H2O  H2 + O2 Reactants  Products

12. Notes • Possible clues to a chemical change/reaction include energy transfer, a color change, the production of a gas, or the forming of a precipitate. • A precipitate is a solid that forms and settles out of a liquid mixture during a reaction.

13. Notes • During a chemical reaction or physical change, the mass of the products always equals the mass of the reactants. • This is the Law of Conservation of Mass. Mass can not be created or destroyed.

14. Notes

15. Question 1 Identify the following as mixtures, elements or compounds: Green ink O2 Fruit punch Salt, NaCl

16. Question 2 Identify the following as mixtures, elements or compounds: Copper Ice Sugar water CaS

17. Question 3 Identify the following as mixtures, elements or compounds: Sugar, C6H12O6 soda CH4 Fluorine

18. Question 4 • In your own words, what is the difference between a pure substance and a mixture?

19. Question 5 Classify the following as homogenous or heterogenous mixtures: • Food coloring • Ice cubes in soda • mouthwash • mashed unpeeled potatoes

20. Question 6 What is the difference between a physical and chemical change?

21. Exit Slip Classify each of the following as a physical or chemical change: Explain why. A copper wire is bent Charcoal burns in a grill Bread dough rises when yeast is added Sugar dissolves in water