1. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 1 Chapter 13 States of Matter Gases, Liquids and Solids

2. States of Matter

3. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 3 Figure 10.1 Schematic Representations of the Three States of Matter

5. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 5 INDIVIDUAL MOLECULES FAR APART PARTICLES INTERACTING VERY LITTLE

6. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 6 MOTION OF MOLECULES IS INCREASE GREATER MOVEMENT GREATER DISORDER

7. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 7 MOLECULES ARE VIRTUALLY LOCKED IN PLACE CAN VIBRATE ABOUT THEIR POSITIONS VERY ORGANIZED

8. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 8 Section 13.1 The Nature of Gases

9. Kinetic Energy Energy due to the motion of an object. –It includes the vibrations and movement within and between the particles.

10. In science, temperature refers to the kinetic energy of an object,

11. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 11 Kinetic Molecular Theory Postulates A gas consists of a collection of small particles traveling in straight- line motion and obeying Newton's Laws.

12. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 12 Postulates The molecules in a gas occupy no volume (that is, they are points).

13. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 13 Postulates Collisions between molecules are perfectly elastic (that is, no energy is gained or lost during the collision).

14. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 14 Postulates There are no attractive or repulsive forces between the molecules.

15. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 15 Postulates The average kinetic energy of a molecule is 3/2 kT T is the absolute temperature. k is a constant

16. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 16 http://preparatorychemistry.com/KMT_flash.ht mhttp://preparatorychemistry.com/KMT_flash.ht m http://www.chm.davidson.edu/vce/kineticmole culartheory/basicconcepts.htmlhttp://www.chm.davidson.edu/vce/kineticmole culartheory/basicconcepts.html

17. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 17 Gas Pressure.

18. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 18 Gas Pressure Force exerted by a gas per unit area

19. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 19 Gases. The gas molecules are in constant motion, and so they regularly hit the walls of the container.

20. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 20 Gases. The force of the gas molecules hitting the walls of the container is called the Gas Pressure.

21. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 21 The more gas molecules there are, the more often the walls of the container are hit, therefore the Gas Pressure is higher..

22. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 22 If the temperature (energy) of the gas is increased the molecules move faster and so hit the walls harder causing the Gas Pressure to rise also.

23. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 23 Measuring Pressure. Vacuum.

24. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 24 Measuring Pressure. Vacuum. Gas Pressure.

25. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 25 Measuring Pressure. Vacuum. Gas Pressure.

26. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 26 Measuring Pressure. Pressure is enough to push 20 cm/H2O………or 10 mm/Hg…….. Manometer. Vacuum. Gas Pressure.

27. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 27 Space is a vacuum. Atmosphere is a gas (Air). Air molecules hit the surface of the earth.

28. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 28

29. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 29 Atmospheric Pressure Pressure of the Air molecules hitting the earth. (or any other surface in the atmosphere). 14 lbs. per square inch

30. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 30 Atmospheric Pressure. P atm = 760 mm/Hg (compared to a vacuum).

31. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 31 We are so accustomed to Atmospheric Pressure that we forget its there.

32. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 32 Atmospheric Pressure = Weight of the Air Results from the mass of the air being pulled toward the center of the earth by GRAVITY. Measures using a barometer.

33. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 33 Figure 5.2 A Torricellian Barometer At sea level = 760 mm Hg At elevation of 9600 feet = 520 mm Hg

34. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 34 Pressure 4 is equal to force/unit area 4 SI units = Newton/meter 2 = 1 Pascal (Pa) 4 1 standard atmosphere = 101,325 Pa 4 1 standard atmosphere = 1 atm = 760 mm Hg = 760 torr

35. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 35 Pressure Units 1 atmosphere (atm) = 760 mm Hg = 760 torr = 101,325 Pa = 29.92 inch Hg = 14.7 lb/ in 2 (psi)

36. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 36 Section 13.2 The Nature of Liquids

37. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 37 Liquids Particles in a liquid are attracted to each other. More dense than gases

38. Particles attracted to each other, but more easily separate

39. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 39 Some Properties of a Liquid Surface Tension: The resistance to an increase in its surface area (polar molecules). Capillary Action: Spontaneous rising of a liquid in a narrow tube. Viscosity: Resistance to flow (molecules with large intermolecular forces).

40. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 40 Surface Tension UNEVEN PULL OF MOLECULES AT THE SURFACE

41. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 41 Figure 10.6 Molecules in a Liquid

42. How does a liquid turn into a gas? It needs enough kinetic energy!!! Called Vaporization 2 ways to vaporize: –1. evaporation- occurs at the surface of a liquid –2. boiling- occurs throughout the liquid.

43. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 43 Liquids Vapor Pressure: Measure of the force exerted by a gas above a liquid. Increasing Temperature increases vapor pressure.

44. Some molecules will condense back into a liquid. A dynamic equilibrium exists between the vapor and the liquid.

45. Vapor pressure increases with Temperature. 13. 2

46. Boiling Point A liquid boils when its vapor pressure is equal to the external pressure.

47. The normal boiling point is the boiling point of a liquid at atmospheric pressure (1 atm or 101.3 kPa)

48. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 48 Section 13.3 The Nature of Solids

49. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 49 Solids Generally described as an orderly arrangement of particles in fixed positions.

50. Solids Most solids have a special type of pattern that the molecules arrange in.

51. Solid Water – ICE!

52. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 52 Types of Solids Crystalline Solids: highly regular arrangement of their components Amorphous solids: considerable disorder in their structures (glass).

53. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 53 Crystalline Solid Lattice: A 3-D system of points designating the centers of components that make up the substance.

54. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 54 Unit Cell Smallest repeating unit of the lattice.

55. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 55 Crystalline Solid Unit Cell: The smallest repeating unit of the lattice. Three common types: 4 simple cubic 4 body-centered cubic 4 face-centered cubic

56. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 56 Figure 10.9 Three Cubic Unit Cells and the Correspond ing Lattices

57. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 57 Figure 10.12 Examples of Three Types of Crystalline Solids

58. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 58 Allotropes Two or more different forms of the same element in the same physical state. Allotropes of carbon: diamond, graphite and buckminsterfullerene

59. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 59 Diamond

60. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 60 Graphite

61. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 61 Buckminsterfullerene

62. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 62 http://preparatorychemistry.com/KMT.html

63. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 63 Section 13.4 Changes of State

64. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 64 CHANGES OF STATE (PHASE TRANSISTIONS) 1) MELTING: s l 2) FREEZING: l s 3) VAPORIZATION: l g 4) SUBLIMATION: s g 5)CONDENSATION: LIQUEFACTION: g l DEPOSITION: g s

65. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 65 PHASE DIAGRAMS GRAPHICAL WAY TO SUMMARIZE THE PHASES OF A SUBSTANCE AS A FUNCTION OF TEMPERATURE ANE PRESSURE DIAGRAMS NOT DRAWN TO SCALE

66. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 66 The Phase Diagram for Water

67. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 67 Figure 10.52 The Phase Diagram for Carbon Dioxide

68. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 68 TRIPLE POINT REPRESENTS TEMPERATURE AND PRESSURE AT WHICH 3 PHASES OF A SUBSTANCE COEXIST IN EQUILIBRIUM FOR WATER, – 0.016 °C, 0.00603 atm (0.61 kPa).

69. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 69 CRITICAL POINT CRITCAL TEMPERATURE: TEMPERATURE ABOVE WHICH THE VAPOR CANNOT BE LIQUEFIED NO MATTER WHAT PRESSURE IS APPLIED CRITICAL PRESSURE: VAPOR PRESSURE AT THE CRITICAL TEMPERATURE WATER: 374°C, 218 atm.