Investigate (09/10/13)

1. Investigate (09/10/13) • In your Notebook, prepare a data table like the one on page 121 for all 6 substances. No column for filter exercise! • Work with the students at your table. • Follow the instructions on page 120 -121, start with 3) do not do last bullet.

2. Warm up(09/10/13)Pure Substances vs Mixtures 9-9-2013 Look at each picture below, and for each item, be prepared to answer Is it a mixture or a compound? Is it a solution? Is it a suspension? Is it a colloid? Is it homogeneous or heterogeneous? How can we tell the difference? How are mixtures similar or different from compounds? Write down the items below and tell which is a mixture and which is a

3. Matter and Change Chemistry

4. Physical Changes • Physical change: a change in the physical properties of a substance. • Composition does not change. • Phase changes (like liquid to gas) • Evaporation, freezing, condensing, subliming, etc. • Tearing or cutting the substance

5. Chemical Change • A change that produces matter with a different composition than the original matter. • Atoms rearrange themselves into new combinations. • All chemical reactions

6. Burning of MethaneCH4 +2O2 CO2 + 2H2O

7. Recognizing a Chemical Change • permanent color change • gas produced (odor or bubbles) • precipitate (solid) produced • light given off • heat released (exothermic) or absorbed (endothermic) • examples include decomposing, rusting, exploding, burning, or and oxidizing.

8. Quick Quiz When one substances turns into another, what kind of change has taken place? A.chemical reaction B.physical reaction C.extensive reaction D.nuclear reaction

9. Change of Phase Melting solid  liquid Condensation gas  liquid Freezing liquid  solid Evaporation liquid  gas Sublimation solid  gas Boiling: Evaporation occurring beneath the liquid’s surface.

10. Temperature vs Time Phase Change Graph

11. Is changing phase a physical or chemical change?

12. Water is a compound. All the components are the same—H2O molecules. Pure Substance Matter that has a uniform and definite composition. Elements- cannot be broken down chemically into simpler substances Compounds-all the components are the same (but could be chemically broken down into elements)

13. Mixture: a physical blend of two or more substances that are not chemically combined. Homogeneous-mixture has the same properties/composition throughout. Homogeneous means the particles are evenly distributed Heterogeneous- Not uniform composition Mixtures can be physically separated. Mixtures exhibit physical properties similar to the components of the mixture.

14. Homogenous Mixtures Solutions • A solution is a homogeneous mixture formed when one substance dissolves in another. • It is the best mixed of all mixtures. • The substance that is dissolved is the solute and the substance that does the dissolving is the solvent.

15. Heterogenous Mixtures Colloids • Colloidsare mixtures, and look like solutions, but their particles are too small to settle to the bottom of their container over time. • Colloids can not be filtered out. • Colloids obey the Tyndall effect • the particles are mixed together but not dissolved • Examples of colloids are mayonnaise, egg whites, and gelatin.

16. Heterogenous Mixtures Tyndall effect • Tyndall effectis occurring if you shine a flashlight through a jar of liquid and see the light beam. • This distinguishes a colloid from a solution.

17. Heterogenous Mixtures Suspensions In a mixture called a suspensionthe particles are very large and will settle out upon standing. Suspensions can be filtered. Examples include muddy water, sand in water, paint, dust in air, flour in water Muddy water, will settle when it is left still for a period of time.

18. Types of mixtures • How can you tell the difference between a solution, a colloid and a suspension? First, try filtering it, then look for the Tyndall effect.

19. Mixtures can be physically separated. • Mixtures exhibit physical properties similar to the components of the mixture. • To separate, use differences in the physical properties of the components of the mixture.

20. Filtration: separates a solid from a liquid in a heterogeneous mixture

21. Distillation: -separate dissolved solids from a liquid -uses boiling and condensation.

22. Learning Check Identify if the following are 1) Homogeneous or 2) Heterogenous • 1perfect, pure air 4. 2salad dressing • 1ink 5. 1coffee • 1soft drink 6. 2Chicken noodle soup

23. Learning Check Circle the solute and underline the solvent • 50 g of water and 5 g NaCl • 2. 20 g copper and 50 g zinc 3. 30%water and 70% alcohol 4. 18.0 L of nitrogen & 12.0 L of oxygen

24. Warm upPure Substances vs Mixtures 9-9-2013 Look at each picture below, and for each item, be prepared to answer Is it a mixture or a compound? Is it a solution? Is it a suspension? Is it a colloid? Is it homogeneous or heterogeneous? How can we tell the difference? How are mixtures similar or different from compounds? Write down the items below and tell which is a mixture and which is a

25. Today’s Activity • Read Chem Talk on page 122 • Draw either a Venn Diagram or table that compares solutions, suspensions and colloids. Tomorrow night is OPEN HOUSE !! Please remind your parents!