Chemistry Matter and Change

1. Chapter 3 Li 6.94 Chemistry Matter and Change Unit 02- Matter Matter- Properties and Changes

2. Chapter Menu Unit 02- Matter and Periodicity Macroscopic Matter mixtures phase changes SOM separation Rf solubility Atomic Structure atomic models radioactive decay light electron configs quantum numbers Periodicity trends Coulomb’s Law Zeff and n, shells atomic radius ionic radius ionization energy PES electron affinity electronegativity

3. Chapter Menu Chapter 03- Matter—Properties and Change BIG IDEA Everything is made of matter. 3.1 Properties of Matter Most common substances exist as solids, liquids, and gases, which have diverse physical and chemical properties. 3.2 Changes in Matter Matter can undergo physical and chemical changes. 3.3 Mixtures of Matter Most everyday matter occurs as mixtures—combinations of two or more substances. 3.4 Elements and Compounds A compound is a combination of two or more elements.

4. Section 3.1 Properties of Matter Most common substances exist as solids, liquids, and gases, which have diverse physical and chemical properties. • Identify the characteristics of a substance. • Distinguish between physical and chemical properties. • Differentiate among the physical states of matter. Section 3-1

5. Substances • Matter is anything that has mass and takes up space (volume). • If all matter has mass and volume, then all matter has a density! • Matter is everything around us. • Matter with a uniform and unchanging composition is a substance. Section 3-1

6. States of Matter Definite volume Definite shape Definite volume Shape of container No definite volume Shape of container

7. Physical Properties of Matter • A physical propertyis a characteristic that can be observed or measured without changing the sample’s composition. Physical Properties of Common Substances Both qualitative and quantitative characteristics Density Section 3-1

8. Physical Properties of Matter (cont.) There are two types of Physical Properties • Extensive properties dependent on the amount of substance present, such as mass, length, or volume • Intensive properties NOT dependent of the amount of substance present, such as density, color, or specific heat. ex- “outside” in- “innate qualities”

9. Chemical Properties of Matter • The ability of a substance to combine with or change into one or more other substances is called a chemical property. • Iron forming rust • Sulfuric Acid poured onto Copper + + Cu(s) H2SO4 CuSO4 H2(g) • A substance can change form–an important concept in chemistry. • Chemical properties can change with specific environmental conditions, such as temperature and pressure. Section 3-1

10. Observing Properties of Matter Properties of Copper Intensive or extensive properties? Section 3-1

11. B Density is what kind of property? A.atomic B.intensive C.extensive D.dependent • A • B • C • D Section 3.1 Assessment Section 3-1

12. C What defines a gas? A.Gases have a definite volume and shape. B.Gases have a definite volume but take the shape of their container. C.Gases have no definite volume or shape. D.Gases have a definite shape but no definite volume. • A • B • C • D Section 3.1 Assessment Section 3-1

13. Section 3.2 Changes in Matter Matter can undergo physical and chemical changes. • Define physical change and list several common physical changes. • Define chemical change and list several indications that a chemical change has taken place. • Apply the law of conservation of mass to chemical reactions. Section 3-2

14. Physical Changes • A change that alters a substance without changing its composition is known as a physical change. • A phase changeis a transition of matter from one state to another. • Boiling, freezing, melting, and condensing all describe phase changes in chemistry. Section 3-2

15. Intermolecular Forces (IMF) The States of Matter are governed by the strength of IMF. • IMF’s are the weak forces of attraction between molecules or neutral atoms. • IMF’s are not the same thing as the much stronger interactions between atoms in compounds, that we normally call “bonds”. Makes States of Matter Makes Compounds States of Matter\ Intermolecular Forces (IMF)

16. Intermolecular Forces (IMF) The States of Matter are governed by the strength of IMF. Think of IMF’s as the Velcro™ between molecules. • The stronger the IMF, the stickier the molecule; greater chance it will be a (l) or (s). • The weaker the IMF, the less sticky the molecule is; and the greater chance it will be a (g). Very Sticky Sticky Not Sticky States of Matter\ Intermolecular Forces (IMF)

17. States of Matter Heat Energy (Joules, J) can do many things to compounds. • Break individual bonds • Makes molecules move (bend, stretch, vibrate, rotate) • Move compounds through space (translational motion), which we call temperature (Kelvin, K) • Break IMF Types of Molecular Movement States of Matter\ Intermolecular Forces (IMF)

18. States of Matter Hydrogen bonds between water molecules The breaking of IMF’s leads to phase changes! • The temperature (translational movement) doesn’t change during a phase change. • All heat energy goes into breaking IMF during a phase change. Solid Liquid Gas Every molecule is H-bonded Some molecules are H-bonded No molecules are H-bonded Less Heat More Heat States of Matter\ Intermolecular Forces (IMF)

19. “Stair-Step Graph” • What do the 2 axes indicate. • What are their units? • Are Temperature and Heat the same thing? GAS Vaporize (Boil) Condense LIQUID Fusion (melt) Freezing Temperature SOLID Phase Changes Less Heat More Heat Heat Energy Section 3-2

20. Physical Changes Use water as an example, since you innately understand it better. Steam Boiling point: 100ºC Steam / water single phase Melting point: 0ºC water Ice / water single phase Temperature ICE Both phases exist at one time. Energy is still added, but temperature doesn’t change until only one phase exists During a phase change, all energy goes into breaking IMF! single phase Heat Energy Section 3-2

21. Physical Changes The amount of IMF dictate phase changes. Heat breaks IMF! Steam single phase Large energy required to break all IMF water ALL IMF intact No IMF intact single phase Temperature ICE Some IMF intact single phase Less Heat More Heat Heat Energy Section 3-2

22. Physical Changes The magnitude of the energy changes at each separate transition are identical, only the sign will change. ∆H = enthalpy (heat) GAS +∆Hvaporize -∆Hcondensation LIQUID +∆Hfusion -∆Hfreeze +∆Hfusion=−∆Hfreeze +∆Hvaporize=−∆Hcondensation Temperature The system requires energy for fusion and vaporization and releases energy for condensation and freezing. SOLID Less Heat More Heat Heat Energy Section 3-2

23. Physical Changes a. Write the correct state of matter in each “state” box. b. Write the number of each transition type in each phase change box state • Vaporize • Freeze • Condense • Deposition • Fusion • Sublime State Temperature state Less Heat More Heat Heat Energy Section 3-2

24. Physical Changes • ____________ • ____________ • ____________ • ____________ • ____________ • ____________ A state 1 2 3 B State Temperature • ____________ • ____________ • ____________ 4 C state Less Heat More Heat Heat Energy Section 3-2

25. Physical Changes “Skipping” the liquid phase depends on temperature and pressure (See the Y-graph on next page) Sublimation: solid to gas (skips liquid) Deposition: gas to Solid (skips liquid) “Gases deposit as solids” Deposition Sublimation Section 3-2

26. “Y” graph Temperature and Pressure dictate phase changes High pressure Low temperature High IMF phase change Intermediate SOLID LIQUID phase change Low pressure High temperature Low IMF GAS phase change

27. “Y” graph Temperature and Pressure dictate phase changes Fusion (melt) Freezing SOLID LIQUID Vaporize (Boil) Condense GAS Sublimation Deposition

28. At the Triple Point, a liquid boils and freezes at the same time. A liquid can make a gas and a solid at the same time! 3-state phase change Melting Vaporizing 2-state phase changes

29. “Y” graph Temperature and Pressure dictate phase changes SOLID LIQUID GAS Section 3-2

30. A supercritical fluid represents an intermediate phase between a liquid and gas. Rank each phase from most dense to least dense.

31. Comparing two different compounds Water (H2O) Carbon Dioxide (CO2) Water is unique with negative slope 1 atm- Pressure (atm) 1 atm- Normal atmospheric pressure is 1 atm • H2O can melt at 1 atm • CO2 can only sublime at 1 atm

32. Conservation of Mass • The law of conservation of massstates that mass is neither created nor destroyed in a chemical reaction, it is conserved. • The mass of the reactants equals the mass of the products. massreactants = massproducts • Each individual element has an identical mass • Each oxygen atom has a mass ~ 16 g / mol • Each hydrogen has a mass of ~ 1 g/ mol • Instead of measuring the mass, you can count the atoms! O: 2 O: 2 H: 4 H: 4 Section 3-2

33. A 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 • A • B • C • D Section 3.2 Assessment Section 3-2

34. D The law of conservation of mass states that: A.Matter can be created and destroyed. B.Matter can be created but not destroyed. C.The products of a reaction always have a greater mass than the reactants. D.The products of a reaction must have the same mass as the reactants. • A • B • C • D Section 3.2 Assessment Section 3-2

35. Matter Matter can either be a pure substance or a mixture, or combination of two or more pure substances A and B A or B Section 3-4

36. Mixtures A mixtureis a combination of two or more pure substances in which each pure substance retains its individual chemical properties. • A homogenous mixture is a mixture where the composition is constant throughout. • Homogeneous mixtures are also called solutions. • A heterogeneous mixture is a mixture where the individual substances remain distinct. Section 3-3

37. Mixtures Homogeneous Homo- same -geneous: “genos”, kind Heterogeneous hetero- different -geneous: “genos”, kind One way to spot the difference is just by looking at it! Salad Dressing Section 3-3

38. Mixtures (cont.) Homogeneous mixtures are called solutions (soln). Types of Solutions Systems Section 3-3

39. Separating Mixtures There are multiple ways to separate mixtures. Mixture: Combination of two or more substances • Filtration • Distillation • Crystallization • Sublimation • Chromatography Section 3-3

40. Separating Mixtures • Filtrationis a technique that uses a porous barrier to separate a solid from a liquid in a heterogeneous mixture. • Distillationis a separation technique for homogeneous mixtures that is based on the differences in boiling points of substances. • Crystallizationis a separation technique for homogenous mixtures that results in the formation of pure solid particles from a solution containing the dissolved substance. • Sublimationis the process of a solid changing directly to a gas, which can be used to separate mixtures of solids when one sublimates and the other does not. • Chromatographyis a technique that separates the components of a mixture on the basis of tendency of each to travel across the surface of another material. Section 3-3

41. Separating Mixtures Filtrationis a technique that uses a porous barrier to separate a solid from a liquid in a heterogeneous mixture. solid Liquid from Solid soln Section 3-3

42. Separating Mixtures Distillationis a separation technique for homogeneous mixtures that is based on the differences in boiling points of substances. Liquid from Solid Liquid from liquid Section 3-3

43. Separating Mixtures Distillationis a separation technique for homogeneous mixtures that is based on the differences in boiling points of substances. Two important businesses, drinkin’ and drivin’ - they don’t mix! Liquid from other Liquids Section 3-3

44. Separating Mixtures Crystallizationis a separation technique for homogenous mixtures that results in the formation of pure solid particles from a solution containing the dissolved substance. Oops! I want my solid back! Yeah! I got my solid back! Rock Candy (Sugar water) Solid from Liquid Section 3-3

45. Separating Mixtures Crystallography leads to protein structure which leads to better understanding of protein function and possible new drugs. Protein Crystallography Section 3-3

46. Separating Mixtures Overview of the X-Ray Crystallographic Method Section 3-3

47. Separating Mixtures Crystallography leads to protein structure which leads to better understanding of protein function and possible new drugs. HIV-1 Proteins HIV-1 Protease Protein inhibitor found active site Section 3-3

48. Separating Mixtures Sublimationis the process of a solid changing directly to a gas, which can be used to separate mixtures of solids when one sublimates and the other does not. Dry Ice, CO2, sublimes “Wet” Ice, H2O, melts Section 3-3

49. Separating Mixtures Chromatographyis a technique that separates the components of a mixture on the basis of tendency of each to travel across the surface of another material. Dyes farthest away from spot are more soluble in the solvent than the other dyes. Section 3-3

50. Rf factor Distance solute traveled, divided by distance solvent traveled.