Classification of Matter

1. Classification of Matter Use to make foldable The terms in red are your voc. terms.

2. Pure Substances • Pure Substance that cannot be broken down into any other substances by chemical or physical means Gold - element Manganese Dioxide - compound

3. Pure Substance • Element • composed of identical atoms • EX: copper wire, aluminum foil Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

4. Pure Substances • Compound • composed of 2 or more elements in a fixed ratio • properties differ from those of individual elements • Chemical bonds hold the elements together • EX: table salt (NaCl) Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

5. Pure Substances - FYI Law of Definite Composition • A given compound always contains the same, fixed ratio of elements. Two different compounds, each has a definite composition Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

6. Molecules • Groups of two or more atoms bound by chemical bonds • Can be two of the same element

7. Chemical Formula-Extra Info • Shows the compound and the ratio of atoms

8. Diatomic Elements, 1 and 7 H2 O2 F2 N2 Cl2 Br2 F2

9. Matter Flowchart Examples: • graphite • pepper • sugar (sucrose) • paint • soda element hetero. mixture compound hetero. mixture solution homo. mixture Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

10. Classification of Matter hetero- geneous mixture no uniform properties? no solution fixed composition? no element chemically decomposable? yes compound http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld003.htm

11. Both elements and compounds have a definite makeup and definite properties. Compounds two or more kinds of atoms that are bonded Mixtures two or more substances that are physically mixed Elements only one kind of atom; atoms are bonded it the element is diatomic or polyatomic two or more kinds of and substance with definite makeup and properties Packard, Jacobs, Marshall, Chemistry Pearson AGS Globe, page (Figure 2.4.1)

12. Mixtures Variable combination of two or more pure substances. Each keep individual properties Homogeneous- Evenly Mixed cannot see different parts. (Same) Heterogeneous – Can see different parts (different) Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

13. Tyndall Effect • The scattering of light by particles in a mixture • http://www.youtube.com/watch?v=gheuYqQ6phE&feature=related

14. Mixtures Solution • homogeneous • very small particles • no Tyndall effect • particles don’t settle • EX: • rubbing alcohol (ethyl alcohol and water) • Air (nitrogen and oxygen) Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

15. Mixtures Colloid • heterogeneous • medium-sized particles • Tyndall effect • particles don’t settle • Particles scatter light • EX: • Milk • Clouds • Smoke • mayo Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

16. Mixtures Suspension • heterogeneous • large particles • Tyndall effect • particles settle • EX: • fresh-squeezed lemonade • Sand in water Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

17. Mixtures Examples: • mayonnaise • muddy water • fog • saltwater • Italian salad dressing colloid suspension colloid solution suspension Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

18. Elements, Compounds, and Mixtures oxygen atoms hydrogen atoms hydrogen atoms (b) a compound (water) (c) a mixture (hydrogen and oxygen) (d) a mixture (hydrogen and oxygen) (a) an element (hydrogen) Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 68

19. MATTER yes no Can it be physically separated? MIXTURE PURE SUBSTANCE yes no yes no Is the composition uniform? Can it be chemically decomposed? Homogeneous Mixture (solution) Heterogeneous Mixture Compound Element Colloids Suspensions Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

20. Classification of Matter MATTER (gas. Liquid, solid, plasma) Separated by PURE SUBSTANCES MIXTURES physical means into Separated by COMPOUNDS ELEMENTS HOMOGENEOUS MIXTURES HETEROGENEOUS MIXTURE chemical means into Kotz & Treichel, Chemistry & Chemical Reactivity, 3rd Edition , 1996, page 31

21. Classification of Matter Matter Physically separable Substance Definite composition (homogeneous) Mixture of Substances Variable composition Chemically separable Element (Examples: iron, sulfur, carbon, hydrogen, oxygen, silver) Compound (Examples: water. iron (II) sulfide, methane, Aluminum silicate) Homogeneous mixture Uniform throughout, also called a solution (Examples: air, tap water, gold alloy) Heterogeneous mixture Nonuniform distinct phases (Examples: soup, concrete, granite)

22. Mixture vs. Compound Alike Different Different Involve substances Variable Composition Fixed Composition Topic Topic No bonds between components Contain two or more elements Bonds between components Mixture Compound Can be separated by physical means Can be separated into elements Can ONLY be separated by chemical means

23. Compounds vs. Mixtures • Compounds have properties that are uniquely different from the elements from which they are made. • A formula can always be written for a compound • e.g. NaCl  Na + Cl2 • Mixtures retain their individual properties. • e.g. Salt water is salty and wet

24. Top TenElements in the Universe • Percent • Element (by atoms) • Hydrogen 73.9 • Helium 24.0 • Oxygen 1.1 • Carbon 0.46 • Neon 0.13 • Iron 0.11 • Nitrogen 0.097 • Silicon 0.065 • Magnesium 0.058 • Sulfur 0.044 A typical spiral galaxy (Milky Way is a spiral galaxy) Zumdahl, Zumdahl, DeCoste, World of Chemistry2002, page 26

25. The Composition of Air Nitrogen Helium Oxygen Air Neon Water vapor Carbon dioxide Argon Zumdahl, Zumdahl, DeCoste, World of Chemistry2002, page 34

26. Chart Examining Some Components of Air Nitrogen consists of molecules consisting of two atoms of nitrogen: Oxygen consists of molecules consisting of two atoms of oxygen: Water consists of molecules consisting of two hydrogen atoms and one oxygen atom: Argon consists of individual argon atoms: Carbon dioxide consists of molecules consisting of two oxygen atoms and one carbon atom: Neon consists of individual neon atoms: Helium consists of individual helium atoms: N2 O2 H2O Ar CO2 Ne He Zumdahl, Zumdahl, DeCoste, World of Chemistry2002, page 35

27. Reviewing ConceptsClassifying Matter • Why does every sample of a given substance have the same properties? • Explain why the composition of an element is fixed. • Describe the composition of a compound. • Why can the properties of a mixture vary? • On what basis can mixtures be classified as solutions, suspensions, or colloids?

28. Separating a Mixture

29. Separating a Mixture • Chromatography - To separate different colored dyes. The dyes travel up the chromatography paper at different distances before they cannot remain in solution. The more soluble dyes move further up than the less soluble ones, hence separating from each other.

30. Separating a Mixture • Distillation - to separate and collect a liquid from a solution of a soluble solid. The solution is heated in a flask until the liquid boils. The vapor produced passes into the condenser where it is cooled and condenses to a liquid. The pure liquid (distillate) is collected in a beaker.

31. Separating a Mixture Evaporation – This method is suitable to separate a soluble solid from a liquid. If the solution is heated, the liquid evaporates leaving the solid behind.

32. Separating a Mixture Fractional Distillation - This is a special type of distillation used to separate a mixture of liquids. Different liquids boil at different temperatures. When heated, they boil off and condense at different times. The apparatus features a fractionating column, which ensures that only the liquid boils at its boiling point will pass into the condenser.

33. Separating a Mixture Filtration – To separate an insoluble solid from a liquid. The solid remains in the filter paper and the liquid goes through the paper into the beaker.

34. Separating a Mixture • Click for link – Setup for each type