1. End Show © Copyright Pearson Prentice Hall Slide 1 of 21 Mixtures Panning is one way to separate gold from a mixture of gold and materials such as sand or gravel. A pan containing the mixture is place underwater and shaken vigorously from left to right. You will learn how to classify and separate mixtures. 2.2

2. End Show © Copyright Pearson Prentice Hall Mixtures Slide 2 of 21 > Classifying Mixtures How can mixtures be classified? 2.2

3. End Show Slide 3 of 21 © Copyright Pearson Prentice Hall > Mixtures Classifying Mixtures A salad bar provides a range of items. Customers choose how much of each item to use in their salads. Each salad has a different composition. 2.2

4. End Show © Copyright Pearson Prentice Hall > Slide 4 of 21 Mixtures Classifying Mixtures A mixture is a physical blend of two or more pure substances. Based on the distribution of their components, mixtures can be classified as heterogeneous mixtures or as homogeneous mixtures. 2.2

5. End Show Slide 5 of 21 © Copyright Pearson Prentice Hall > MixturesClassifying Mixtures Heterogeneous Mixtures A mixture in which the composition is not uniform throughout is a heterogeneous mixture. “hetero-” = different If you can see that two different substances are present, it is heterogeneous. 2.2

6. End Show Slide 6 of 21 © Copyright Pearson Prentice Hall > MixturesClassifying Mixtures Homogeneous Mixtures A mixture in which the composition is uniform throughout is a homogeneous mixture. “homo” = same Another name for a homogeneous mixture is a solution. If a mixturlooks the same throughout, it may be a homogenous mixture 2.2

7. End Show Slide 7 of 21 © Copyright Pearson Prentice Hall > Mixtures 2.2 Classifying Mixtures The term phase is used to describe any part of a sample with uniform composition and properties. A homogenous mixture consists of a single phase. A heterogeneous mixture consists of two or more phases.

8. End Show Slide 8 of 21 © Copyright Pearson Prentice Hall > Mixtures 2.2 Classifying Mixtures When oil and vinegar are mixed they form layers, or phases. The oil phase floats on the water phase.

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12. © Copyright Pearson Prentice Hall Slide 12 of 21 End Show Practice Problems for Conceptual Problem 2.2 Problem Solving 2.10 Solve Problem 10 with the help of an interactive guided tutorial.

13. End Show © Copyright Pearson Prentice Hall Mixtures Slide 13 of 21 > 2.2 Separating Mixtures How can mixtures be separated?

14. End Show © Copyright Pearson Prentice Hall > Slide 14 of 21 Mixtures Separating Mixtures Differences in physical properties can be used to separate mixtures. 2.2

15. End Show Slide 15 of 21 © Copyright Pearson Prentice Hall > Mixtures Separating Mixtures Filtration The process that separates a solid from the liquid in a heterogeneous mixture is called filtration. Filtration separates the components of a mixture based on a difference in particle size. A colander is used to separate pasta from the water in which it was cooked. This process is a type of filtration. 2.2

16. End Show Slide 16 of 21 © Copyright Pearson Prentice Hall > Mixtures Separating Mixtures Distillation During a distillation, a liquid is boiled to produce a vapor that is then condensed into a liquid. Distillation separates the components of a mixture based on a difference in boiling points. 2.2

17. End Show Slide 17 of 21 © Copyright Pearson Prentice Hall > Mixtures Separating Mixtures Chromatography Chromatography separates homogeneous mixtures based on differences in solubility.. 2.2

18. End Show Slide 18 of 21 © Copyright Pearson Prentice Hall > Mixtures Chromatography You have seen this technique used in CSI when they are comparing DNA or determining the chemicals present in a substance

19. End Show Slide 19 of 21 © Copyright Pearson Prentice Hall > Mixtures Separating Mixtures Crystallization Crystallization is used to separated a homogeneous mixture based a difference in solubility. EX: rock candy http://www.stevespanglerscience.com/experime nt/00000078. 2.2

20. End Show Slide 20 of 21 © Copyright Pearson Prentice Hall > Mixtures Separating Mixtures If a substance appears uniform throughout and cannot be separated by a difference in physical properties, then it is not a mixture. It is a pure substance (element or compound). 2.2

21. End Show © Copyright Pearson Prentice Hall Slide 21 of 21 Section Quiz -or- Continue to: Launch: Assess students’ understanding of the concepts in Section 2.2 Section Quiz. 2.2.

22. © Copyright Pearson Prentice Hall Slide 22 of 21 End Show 2.2 Section Quiz. 1.Which of the following phrases describes a mixture? a.composition varies b.composition may vary c.components cannot be separated

23. © Copyright Pearson Prentice Hall Slide 23 of 21 End Show 2.2 Section Quiz. 2.Which of the following is a homogeneous mixture? a.vinegar b.iron filings in sand c.chicken noodle soup d.muddy water

24. © Copyright Pearson Prentice Hall Slide 24 of 21 End Show 2.2 Section Quiz. 3.Which technique is used to separate homogeneous mixtures? a.filtration b.distillation c.magnetism d.dissolving

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