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Chapter 10 Liquids and Solids. 2 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven States.

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Presentation on theme: "Chapter 10 Liquids and Solids. 2 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven States."— Presentation transcript:

1 Chapter 10 Liquids and Solids

2 2 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven States of Matter and Intermolecular Forces Unit ch.5, 10, 11

3 3 Chapter 10 Table of Contents Copyright © Cengage Learning. All rights reserved 10.1 Intermolecular Forces10.1 Intermolecular Force 10.2 The Liquid State10.2 The Liquid Stat 10.3 An Introduction to Structures and Types of Solids10.3 An Introduction to Structures and Types of Soli 10.4 Structure and Bonding in Metals10.4 Structure and Bonding in Meta 10.5 Carbon and Silicon: Network Atomic Solids10.5 Carbon and Silicon: Network Atomic Soli 10.6Molecular Solids10.6Molecular Soli 10.7Ionic Solids10.7Ionic Soli 10.8Vapor Pressure and Changes of State10.8Vapor Pressure and Changes of Sta 10.9Phase Diagrams10.9Phase Diagra

4 4 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Links to visuals & review Click on the link below and use as you get to visual animations and vocabulary. ahl/chemistry/7e/resources/fae/index.html?l ayer=item&src=ch10/qtiflash_ch10_overvi ew_p1.xml&w=645&h=428http://college.cengage.com/chemistry/zumd ahl/chemistry/7e/resources/fae/index.html?l ayer=item&src=ch10/qtiflash_ch10_overvi ew_p1.xml&w=645&h=428

5 5 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Links to visuals & review Click on the link below and use as you get to visual animations and vocabulary. Alternate 2 link to ch. 10 site ahl/chemistry/7e/improve/improve10.htmlhttp://college.cengage.com/chemistry/zumd ahl/chemistry/7e/improve/improve10.html

6 6 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Intra molecular forces (bonds) govern molecular properties such as molecular geometries and dipole moments. Intermolecular forces determine the macroscopic physical properties of liquids and solids. This chapter: –describes changes from one state of matter to another. –explores the types of intermolecular forces that underlie these and other physical properties of substances. Chapter Preview

7 7 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Intramolecular Bonding “Within” the molecule. Molecules are formed by sharing electrons between the atoms.

8 8 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Molecular Forces Compared

9 9 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Intermolecular Forces EXAMPLES Forces that occur between molecules. They determine melting points, freezing points, and other physical properties. Types of intermolecular forces include: dispersion forces - London dispersion forces Dipole–dipole forces –Hydrogen bonding Intramolecular bonds are stronger than intermolecular forces.

10 10 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Dispersion Forces … exist between any two particles. Also called London forces (after Fritz London, who offered a theoretical explanation of these forces in 1928). Dispersion forces arise because the electron cloud is not perfectly uniform. Tiny, momentary dipole moments can exist even in nonpolar molecules.

11 11 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC London Dispersion Forces Instantaneous dipole that occurs accidentally in a given atom induces a similar dipole in a neighboring atom. Significant in large atoms/molecules. Occurs in all molecules, including nonpolar ones.

12 12 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC London Dispersion Forces Pull from the following link layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428http://college.cengage.com/chemistry/zumdahl/chemistry/7e/resources/fae/index.html? layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428

13 13 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Dispersion Forces Illustrated (1) At a given instant, electron density, even in a nonpolar molecule like this one, is not perfectly uniform.

14 14 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Dispersion Forces Illustrated (2) The region of (momentary) higher electron density attains a small (–) charge … When another nonpolar molecule approaches … … the other end of the molecule is slightly (+).

15 15 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Dispersion Forces Illustrated (3) … this molecule induces a tiny dipole moment … … in this molecule. Opposite charges ________.

16 16 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Strength of Dispersion Forces Dispersion force strength depends on polarizability : the ease with which the electron cloud is distorted by an external electrical field. The greater the polarizability of molecules, the stronger the dispersion forces between them. Polarizability in turn depends on molecular size and shape. Heavier molecule => more electrons => a more- polarizable molecule. As to molecular shape …

17 17 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Molecular Shape and Polarizability Long skinny molecule … … can have greater separation of charge along its length. Stronger forces of attraction, meaning … … higher boiling point. In the compact isomer, less possible separation of charge … … giving weaker dispersion forces and a lower boiling point.

18 18 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Dipole–Dipole Forces A polar molecule has a positively charged “end” (δ+) and a negatively charged “end” (δ–). When molecules come close to one another, repulsions occur between like-charged regions of dipoles. Opposite charges tend to attract one another. The more polar a molecule, the more pronounced is the effect of dipole–dipole forces on physical properties.

19 19 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Dipole–Dipole Interactions Opposites attract!

20 20 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Dipole-Dipole Forces Dipole moment – molecules with polar bonds often behave in an electric field as if they had a center of positive charge and a center of negative charge. Molecules with dipole moments can attract each other electrostatically. They line up so that the positive and negative ends are close to each other. Only about 1% as strong as covalent or ionic bonds.

21 21 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Dipole-Dipole Forces Pull from the following link layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428http://college.cengage.com/chemistry/zumdahl/chemistry/7e/resources/fae/index.html? layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428

22 22 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Hydrogen Bonds A hydrogen bond is an intermolecular force in which: –a hydrogen atom that is covalently bonded to a (small, electronegative) nonmetal atom in one molecule … –is simultaneously attracted to a (small, electronegative) nonmetal atom of a neighboring molecule. Y ––– H Z ~~~~ When Y and Z are small and highly electronegative (N, O, F) … … this force is called a hydrogen bond; a special, strong type of dipole–dipole force.

23 23 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Hydrogen Bonding in Water Blue dotted lines are the intermolecular forces between the water molecules.

24 24 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Hydrogen Bonding Pull from the following link layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428http://college.cengage.com/chemistry/zumdahl/chemistry/7e/resources/fae/index.html? layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428

25 25 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Hydrogen Bonding Strong dipole-dipole forces. Hydrogen is bound to a highly electronegative atom – nitrogen, oxygen, or fluorine.

26 26 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Hydrogen Bonds in Water

27 27 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Hydrogen Bonding in Ice Hydrogen bonding arranges the water molecules into an open hexagonal pattern. “Hexagonal” is reflected in the crystal structure. “Open” means reduced density of the solid (vs. liquid).

28 28 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Hydrogen Bonding in Acetic Acid Hydrogen bonding occurs between molecules.

29 29 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Hydrogen Bonding in Salicylic Acid Hydrogen bonding occurs within the molecule.

30 30 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Intermolecular Hydrogen Bonds Intermolecular hydrogen bonds give proteins their secondary shape, forcing the protein molecules into particular orientations, like a folded sheet …

31 31 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Animation and Questions for Intermolecular Forces Click link below for Intermolecular forces and animations. (needed add’l downloads) /imf2.htmlhttp://www.chem.purdue.edu/gchelp/liquids /imf2.html

32 32 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Intramolecular Hydrogen Bonds … while intramolecular hydrogen bonds can cause proteins to take a helical shape.

33 33 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Example 11.8 –In which of these substances is hydrogen bonding an important intermolecular force: N 2, HI, HF, CH 3 CHO, and CH 3 OH? Explain.

34 34 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check Which are stronger, intramolecular bonds or intermolecular forces? How do you know?

35 35 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Predicting Physical Properties of Molecular Substances Dispersion forces become stronger with increasing molar mass and elongation of molecules. In comparing nonpolar substances, molar mass and molecular shape are the essential factors. Dipole–dipole and dipole-induced dipole forces are found in polar substances. The more polar the substance, the greater the intermolecular force is expected to be. Because they occur in all substances, dispersion forces must always be considered. Often they predominate.

36 36 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Example 11.6 –Arrange the following substances in the expected order of increasing boiling point: carbon tetrabromide, CBr 4 ; butane, CH 3 CH 2 CH 2 CH 3 ; fluorine, F 2 ; acetaldehyde, CH 3 CHO.

37 37 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Homology A series of compounds whose formulas and structures vary in a regular manner also have properties that vary in a predictable manner. This principle is called homology. Example: both densities and boiling points of the straight-chain alkanes increase in a continuous and regular fashion with increasing numbers of carbon atoms in the chain. Trends result from the regular increase in molar mass, which produces a fairly regular increase in the strength of dispersion forces.

38 38 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven QUESTION

39 39 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Videoclip summary Watch the following for intermolecular forces. Click below. stry/chemical-bonds/intermolecular-forces/http://www.brightstorm.com/science/chemi stry/chemical-bonds/intermolecular-forces/

40 40 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven States of Matter Compared Intermolecular forces are of little significance; why? Intermolecular forces must be considered. Intermolecular forces are very important.

41 41 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Phase Changes When a substance changes from solid to liquid to gas, the molecules remain intact. The changes in state are due to changes in the forces among molecules rather than in those within the molecules.

42 42 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Schematic Representations of the Three States of Matter

43 43 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Phase Changes Solid to Liquid  As energy is added, the motions of the molecules increase, and they eventually achieve the greater movement and disorder characteristic of a liquid. Liquid to Gas  As more energy is added, the gaseous state is eventually reached, with the individual molecules far apart and interacting relatively little.

44 44 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Densities of the Three States of Water

45 45 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Melting and Boiling Points In general, the stronger the intermolecular forces, the higher the melting and boiling points.

46 46 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC The Boiling Points of the Covalent Hydrides of the Elements in Groups 4A, 5A, 6A, and 7A

47 47 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check Which molecule is capable of forming stronger intermolecular forces? N 2 H 2 O Explain.

48 48 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check Draw two Lewis structures for the formula C 2 H 6 O and compare the boiling points of the two molecules.

49 49 Section 10.1 Intermolecular Forces Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check Which gas would behave more ideally at the same conditions of P and T? CO or N 2 Why?

50 50 Section 10.2 Atomic Masses Copyright © Cengage Learning. All rights reserved The Liquid State Return to TOC Liquids Low compressibility, lack of rigidity, and high density compared with gases. Surface tension – resistance of a liquid to an increase in its surface area:  Liquids with large intermolecular forces tend to have high surface tensions.

51 51 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Surface Tension To create more surface, the molecules at the surface must be separated from one another.

52 52 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Liquids and Intermolecular Forces Much behavior and many properties of liquids can be attributed to intermolecular forces. Surface tension (  ) is the amount of work required to extend a liquid surface and is usually expressed in J/m 2. Adhesive forces are intermolecular forces between unlike molecules. Cohesive forces are intermolecular forces between like molecules. A meniscus is the interface between a liquid and the air above it. Viscosity is a measure of a liquid’s resistance to flow.

53 53 Section 10.2 Atomic Masses Copyright © Cengage Learning. All rights reserved The Liquid State Return to TOC Liquids Capillary action – spontaneous rising of a liquid in a narrow tube:  Cohesive forces – intermolecular forces among the molecules of the liquid.  Adhesive forces – forces between the liquid molecules and their container.

54 54 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Meniscus Formation Water wets the glass (adhesive forces) and its attraction for glass forms a concave- up surface. What conclusion can we draw about the cohesive forces in mercury?

55 55 Section 10.2 Atomic Masses Copyright © Cengage Learning. All rights reserved The Liquid State Return to TOC Convex Meniscus Formed by Nonpolar Liquid Mercury  Which force dominates alongside the glass tube – cohesive or adhesive forces? cohesive forces

56 56 Section 10.2 Atomic Masses Copyright © Cengage Learning. All rights reserved The Liquid State Return to TOC Concave Meniscus Formed by Polar Water Which force dominates alongside the glass tube – cohesive or adhesive forces? adhesive forces

57 57 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Adhesive and Cohesive Forces The liquid spreads, because adhesive forces are comparable in strength to cohesive forces. The liquid “beads up.” Which forces are stronger, adhesive or cohesive?

58 58 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Capillary Action The adhesive forces wet more and more of the inside of the tiny tube, drawing water farther up the tube.

59 59 Section 10.2 Atomic Masses Copyright © Cengage Learning. All rights reserved The Liquid State Return to TOC Liquids Viscosity – measure of a liquid’s resistance to flow:  Liquids with large intermolecular forces or molecular complexity tend to be highly viscous.

60 60 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Comparing Viscosity Which oil flows more readily? Which oil has stronger intermolecular forces between its molecules? Oil is mostly hydrocarbons; what kind of forces are these?

61 61 Section 10.3 The MoleAn Introduction to Structures and Types of Solids Copyright © Cengage Learning. All rights reserved Return to TOC Solids Amorphous Solids:  Disorder in the structures  Glass Crystalline Solids:  Ordered Structures  Unit Cells

62 62 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Types of Solids Amorphous solids have no significant long-range order. Crystalline solids have atoms/ions/molecules arranged in a regular pattern. Types of crystalline solids include: – Molecular solids, containing molecules held to one another by dispersion/dipole–dipole/ hydrogen bonding forces. – Network (covalent) solids. – Ionic solids. – Metallic solids (metals).

63 63 Section 10.3 The MoleAn Introduction to Structures and Types of Solids Copyright © Cengage Learning. All rights reserved Return to TOC Three Cubic Unit Cells and the Corresponding Lattices

64 64 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Ionic Bonds as “Intermolecular” Forces There are no molecules in an ionic solid, and therefore there can’t be any intermolecular forces. The attractions are electrostatic interionic attractions. Lattice energy (Chapter 9) is a measure of the strength of interionic attraction. The attractive force between a pair of oppositely charged ions increases: –as the charges on the ions increase. –as the ionic radii decrease. Lattice energies increase accordingly.

65 65 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Interionic Forces of Attraction Melting point of NaCl is about 801 o C. Mg 2+ and O 2– have much stronger forces of attraction for one another than do Na + and Cl –. Melting point of MgO is about 2800 o C.

66 66 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Example 11.9 –Arrange the ionic solids MgO, NaBr, and NaCl in the expected order of increasing melting point.

67 67 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Crystal Lattices To describe crystals, three-dimensional views must be used. The repeating unit of the lattice is called the unit cell. There are a number of different types of unit cell; hexagonal, rhombic, cubic, etc. The three types of cubic unit cells are: simple cubic, body-centered cubic (bcc), face-centered cubic (fcc).

68 68 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Cubic Unit Cells The unit cell is a cube in each case. Whole atoms shown for clarity.

69 69 Section 10.3 The MoleAn Introduction to Structures and Types of Solids Copyright © Cengage Learning. All rights reserved Return to TOC Bragg Equation Used to determine the interatomic spacings. n = integer = wavelength of the X rays d = distance between the atoms = angle of incidence and reflection

70 70 Section 10.3 The MoleAn Introduction to Structures and Types of Solids Copyright © Cengage Learning. All rights reserved Return to TOC Bragg Equation

71 71 Section 10.3 The MoleAn Introduction to Structures and Types of Solids Copyright © Cengage Learning. All rights reserved Return to TOC Types of Crystalline Solids Ionic Solids – ions at the points of the lattice that describes the structure of the solid. Molecular Solids – discrete covalently bonded molecules at each of its lattice points. Atomic Solids – atoms at the lattice points that describe the structure of the solid.

72 72 Section 10.3 The MoleAn Introduction to Structures and Types of Solids Copyright © Cengage Learning. All rights reserved Return to TOC Examples of Three Types of Crystalline Solids

73 73 Section 10.3 The MoleAn Introduction to Structures and Types of Solids Copyright © Cengage Learning. All rights reserved Return to TOC Classification of Solids

74 74 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Closest Packing Model Closest Packing:  Assumes that metal atoms are uniform, hard spheres.  Spheres are packed in layers.

75 75 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Animations for Closest Packing Simple Cubic Animation ement/chemistry_chang10e/animations/sphere_packing _simple.swfhttp://glencoe.com/sites/common_assets/advanced_plac ement/chemistry_chang10e/animations/sphere_packing _simple.swf Cubic Closest Packing Animation ement/chemistry_chang10e/animations/sphere_packing _cubic_close.swfhttp://glencoe.com/sites/common_assets/advanced_plac ement/chemistry_chang10e/animations/sphere_packing _cubic_close.swf

76 76 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Close-Packed Structures A close packed structure in two dimensions.

77 77 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Close Packing in Three Dimensions Two layers, stacked, give two different locations for the third layer … Third layer directly above first layer: HCP Third layer over the octahedral holes in the second layer: CCP

78 78 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC The Closest Packing Arrangement of Uniform Spheres aba packing – the 2 nd layer is like the 1 st but it is displaced so that each sphere in the 2 nd layer occupies a dimple in the 1 st layer. The spheres in the 3 rd layer occupy dimples in the 2 nd layer so that the spheres in the 3 rd layer lie directly over those in the 1 st layer.

79 79 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC The Closest Packing Arrangement of Uniform Spheres abc packing – the spheres in the 3 rd layer occupy dimples in the 2 nd layer so that no spheres in the 3 rd layer lie above any in the 1 st layer. The 4 th layer is like the 1 st.

80 80 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Hexagonal Closest Packing

81 81 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Cubic Closest Packing

82 82 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC The Indicated Sphere Has 12 Nearest Neighbors Each sphere in both ccp and hcp has 12 equivalent nearest neighbors.

83 83 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC The Net Number of Spheres in a Face-Centered Cubic Unit Cell

84 84 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check Determine the number of metal atoms in a unit cell if the packing is: a) Simple cubic b) Cubic closest packing a) 1 metal atom b) 4 metal atoms

85 85 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check A metal crystallizes in a face-centered cubic structure. Determine the relationship between the radius of the metal atom and the length of an edge of the unit cell.

86 86 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Example –Copper crystallizes in the cubic close-packed arrangement. The atomic (metallic) radius of a Cu atom is pm. (a) What is the length, in picometers, of the unit cell in a sample of copper metal? (b) What is the volume of that unit cell, in cubic centimeters? (c) How many atoms belong to the unit cell? Example Use the results of Example 11.10, the molar mass of copper, and Avogadro’s number to calculate the density of metallic copper.

87 87 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check Silver metal crystallizes in a cubic closest packed structure. The face centered cubic unit cell edge is 409 pm. Calculate the density of the silver metal. Density = 10.5 g/cm 3

88 88 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Bonding Models for Metals Electron Sea Model Band Model (MO Model)

89 89 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC The Electron Sea Model A regular array of cations in a “sea” of mobile valence electrons.

90 90 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Molecular Orbital Energy Levels Produced When Various Numbers of Atomic Orbitals Interact

91 91 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC The Band Model for Magnesium Virtual continuum of levels, called bands.

92 92 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Metal Alloys Substitutional Alloy – some of the host metal atoms are replaced by other metal atoms of similar size. Interstitial Alloy – some of the holes in the closest packed metal structure are occupied by small atoms.

93 93 Section 10.4 Structure and Bonding in Metals Copyright © Cengage Learning. All rights reserved Return to TOC Two Types of Alloys Brass is a substitutional alloy. Steel is an interstitial alloy.

94 94 Section 10.5 Carbon and Silicon: Network Atomic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Network Solids Pull from the following link l?layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428http://college.cengage.com/chemistry/zumdahl/chemistry/7e/resources/fae/index.htm l?layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428

95 95 Section 10.5 Carbon and Silicon: Network Atomic Solids Copyright © Cengage Learning. All rights reserved Return to TOC The Structures of Diamond and Graphite

96 96 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Network Covalent Solids Network solids have a network of covalent bonds that extend throughout the solid, holding it firmly together. The allotropes of carbon provide good examples. – Diamond has each carbon bonded to four other carbons in a tetrahedral arrangement using sp 3 hybridization. – Graphite has each carbon bonded to three other carbons in the same plane using sp 2 hybridization. – Fullerenes are roughly spherical collections of carbon atoms in the shape of a soccer ball. –A nanotube can be thought of as a plane of graphite rolled into a tube.

97 97 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Crystal Structure of Diamond Three-dimensional network is extremely strong, rigid. What kind of forces must be overcome to melt diamond?

98 98 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Crystal Structure of Graphite Forces between layers are relatively weak. Hexagons of sp 2 -hybridized carbon atoms.

99 99 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Structure of a Buckyball C 60 molecule

100 100 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Structure of a Nanotube A nanotube can be thought of as a sheet of graphite, rolled into a tube, capped with half of a buckyball.

101 101 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven

102 102 Section 10.5 Carbon and Silicon: Network Atomic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Partial Representation of the Molecular Orbital Energies in a) Diamond b) a Typical Metal

103 103 Section 10.5 Carbon and Silicon: Network Atomic Solids Copyright © Cengage Learning. All rights reserved Return to TOC The p Orbitals and Pi-system in Graphite

104 104 Section 10.5 Carbon and Silicon: Network Atomic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Ceramics Typically made from clays (which contain silicates) and hardened by firing at high temperatures. Nonmetallic materials that are strong, brittle, and resistant to heat and attack by chemicals.

105 105 Section 10.5 Carbon and Silicon: Network Atomic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Semiconductors n-type semiconductor – substance whose conductivity is increased by doping it with atoms having more valence electrons than the atoms in the host crystal. p-type semiconductor – substance whose conductivity is increased by doping it with atoms having fewer valence electrons than the atoms of the host crystal.

106 106 Section 10.5 Carbon and Silicon: Network Atomic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Energy Level Diagrams for (a) an n-type Semiconductor (b) a p-type Semiconductor

107 107 Section 10.5 Carbon and Silicon: Network Atomic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Silicon Crystal Doped with (a) Arsenic and (b) Boron

108 108 Section 10.6 Molecular Solids Copyright © Cengage Learning. All rights reserved Return to TOC Pull from the following link layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428http://college.cengage.com/chemistry/zumdahl/chemistry/7e/resources/fae/index.html? layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428

109 109 Section 10.7 Ionic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Pull from the following link layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428http://college.cengage.com/chemistry/zumdahl/chemistry/7e/resources/fae/index.html? layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428

110 110 Section 10.7 Ionic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Three Types of Holes in Closest Packed Structures 1) Trigonal holes are formed by three spheres in the same layer.

111 111 Section 10.7 Ionic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Three Types of Holes in Closest Packed Structures 2) Tetrahedral holes are formed when a sphere sits in the dimple of three spheres in an adjacent layer.

112 112 Section 10.7 Ionic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Three Types of Holes in Closest Packed Structures 3) Octahedral holes are formed between two sets of three spheres in adjoining layers of the closest packed structures.

113 113 Section 10.7 Ionic Solids Copyright © Cengage Learning. All rights reserved Return to TOC For spheres of a given diameter, the holes increase in size in the order: trigonal < tetrahedral < octahedral

114 114 Section 10.7 Ionic Solids Copyright © Cengage Learning. All rights reserved Return to TOC Types and Properties of Solids

115 115 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Ionic Crystal Structures Ionic crystals have two different types of structural units—cations and anions. The cations and anions ordinarily are different sizes. Smaller cations can fill the voids between the larger anions. Where the cations go depends on the size of the cations and on the size of the voids. The smallest voids are the tetrahedral holes, then the octahedral holes, and finally the holes in a cubic structure. Therefore …

116 116 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Ionic Crystal Structures Tetrahedral hole filling occurs when the cations are small; when the radii ratio is: < r c / r a < Octahedral filling occurs with larger cations, when the radii ratio is: < r c / r a < The arrangement is cubic if r c / r a >

117 117 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Unit Cell of Cesium Chloride How many cesium ions are inside this unit cell? How many chloride ions?

118 118 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Unit Cell of Sodium Chloride How many sodium ions are inside this unit cell? How many chloride ions?

119 119 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Experimental Determination of Crystal Structures X rays Angle of diffraction can be used to find distance d, using simple trigonometry.

120 120 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Cumulative Example –Here are some data about an organic compound: Its normal boiling point is a few degrees below that of H 2 O(l), and its vapor density at 99.0 °C and 752 Torr is within 5% of 2.0 g/L. Using these data and other information from this and previous chapters, determine which one of the following compounds it is most likely to be: (a) (CH 3 ) 2 O (b) CH 3 CH 2 CH 2 OH (c) CH 3 CH 2 OCH 3 (d) HOCH 2 CH 2 OH

121 121 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Vaporization and Condensation Vaporization is the conversion of a liquid to a gas. The enthalpy of vaporization ( ΔH vapn ) is the quantity of heat that must be absorbed to vaporize a given amount of liquid at a constant temperature. Condensation is the reverse of vaporization. The enthalpy of condensation ( ΔH condn ) accompanies this change of a gas to a liquid. Enthalpy is a function of state: therefore, if a liquid is vaporized and the vapor condensed at constant temperature, the total ΔH must be zero: ΔH vapn + ΔH condn = 0 ΔH condn = – ΔH vapn

122 122 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven

123 123 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Vapor Pressure The vapor pressure of a liquid is the partial pressure exerted by the vapor when it is in dynamic equilibrium with the liquid at a constant temperature. vaporization LiquidVapor condensation

124 124 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Vapor Pressure Animation vanced_placement/chemistry_chang10e/ani mations/vapor_pressure.swfhttp://glencoe.com/sites/common_assets/ad vanced_placement/chemistry_chang10e/ani mations/vapor_pressure.swf

125 125 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Liquid–Vapor Equilibrium More vapor forms; rate of condensation of that vapor increases … … until equilibrium is attained.

126 126 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Vapor pressure increases with temperature; why?

127 127 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Behavior of a Liquid in a Closed Container a) Initially b) at Equilibrium

128 128 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC The Rates of Condensation and Evaporation

129 129 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Vapor Pressure Pressure of the vapor present at equilibrium. The system is at equilibrium when no net change occurs in the amount of liquid or vapor because the two opposite processes exactly balance each other.

130 130 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check What is the vapor pressure of water at 100°C? How do you know? 1 atm

131 131 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Vapor Pressure

132 132 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Vapor Pressure Liquids in which the intermolecular forces are strong have relatively low vapor pressures. Vapor pressure increases significantly with temperature.

133 133 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Vapor Pressure vs. Temperature

134 134 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Vapor Pressure Curves Which of the five compounds has the strongest intermolecular forces? How can you tell? CS 2 CH 3 OH CH 3 CH 2 OH H2OH2O C 6 H 5 NH 2 What is the vapor pressure of H 2 O at 100 °C, according to this graph? What is the significance of that numeric value of vapor pressure?

135 135 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Clausius–Clapeyron Equation P vap = vapor pressure ΔH vap = enthalpy of vaporization R = J/K·mol T = temperature (in kelvin)

136 136 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check The vapor pressure of water at 25°C is 23.8 torr, and the heat of vaporization of water at 25°C is 43.9 kJ/mol. Calculate the vapor pressure of water at 65°C. 194 torr

137 137 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Changes of State Pull from the following link layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428http://college.cengage.com/chemistry/zumdahl/chemistry/7e/resources/fae/index.html? layer=item&src=ch10/qtiflash_ch10_overview_p1.xml&w=645&h=428

138 138 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC THURS - Left Left off here with quick discussion

139 139 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Heating Curve for Water

140 140 Section 10.8 Vapor Pressure and Changes of State Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check Which would you predict should be larger for a given substance: ΔH vap or ΔH fus ? Explain why.

141 141 Section 10.9 Phase Diagrams Copyright © Cengage Learning. All rights reserved Return to TOC A convenient way of representing the phases of a substance as a function of temperature and pressure:  Triple point  Critical point  Phase equilibrium lines

142 142 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Boiling Point and Critical Point Boiling point: the temperature at which the vapor pressure of the liquid equals the external pressure. Normal boiling point: boiling point at 1 atm. Critical temperature (T c ): the highest temperature at which a liquid can exist. The critical pressure, P c, is the vapor pressure at the critical temperature. The condition corresponding to a temperature of T c and a pressure of P c is called the critical point.

143 143 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven The Critical Point At room temperature there is relatively little vapor, and its density is low. At higher temperature, there is more vapor, and its density increases … … while the density of the liquid decreases; molecular motion increases. At T c, the densities of liquid and vapor are equal; a single phase.

144 144 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven These four gases can’t be liquefied at room temperature, no matter what pressure is applied; why not?

145 145 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Example 11.4 A Conceptual Example –To keep track of how much gas remains in a cylinder, we can weigh the cylinder when it is empty, when it is full, and after each use. In some cases, though, we can equip the cylinder with a pressure gauge and simply relate the amount of gas to the measured gas pressure. Which method should we use to keep track of the bottled propane, C 3 H 8, in a gas barbecue?

146 146 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Phase Changes Involving Solids Melting ( fusion ): transition of solid  liquid. Melting point : temperature at which melting occurs. – Same as freezing point! Enthalpy of fusion, ΔH fusion, is the quantity of heat required to melt a set amount (one gram, one mole) of solid. Sublimation : transition of solid  vapor. –Example: Ice cubes slowly “disappear” in the freezer. Enthalpy of sublimation, ΔH subln, is the sum of the enthalpies of fusion and vaporization. Triple point : all three phases—solid, liquid, vapor—are in equilibrium.

147 147 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Some Enthalpies of Fusion

148 148 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Cooling Curve for Water The liquid water cools until … … the freezing point is reached, at which time the temperature remains constant as solid forms. Once all of the liquid has solidified, the temperature again drops. If the liquid is cooled carefully, it can supercool.

149 149 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Heating Curve for Water The temperature of the solid increases as it is heated … … until the solid begins to melt, at which time the temperature remains constant … … until all the solid is melted, at which time the temperature again rises.

150 150 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Phase Diagrams A phase diagram is a graphical representation of the conditions of temperature and pressure under which a substance exists as a solid, liquid, a gas, or some combination of these in equilibrium. A—B, solid-vapor equilibrium. A—D, solid-liquid equilibrium. A—C, liquid-vapor equilibrium. Triple point

151 151 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Phase Diagram for HgI 2 HgI 2 has two solid phases, red and yellow. As the vessel is allowed to cool, will the contents appear more red or more yellow?

152 152 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Phase Diagram for CO 2 Note that at 1 atm, only the solid and vapor phases of CO 2 exist.

153 153 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Phase Diagram for H 2 O

154 154 Hall © 2005 Prentice Hall © 2005 General Chemistry 4 th edition, Hill, Petrucci, McCreary, Perry Chapter Eleven Example 11.5 A Conceptual Example –In Figure 11.14, 50.0 mol H 2 O(g) (steam) at °C and 1.00 atm is added to an insulated cylinder that contains 5.00 mol H 2 O(s) (ice) at 0 °C. With a minimum of calculation, use the data provided to determine which of the following will describe the final equilibrium condition: (a) ice and liquid water at 0 °C, (b) liquid water at 50 °C, (c) steam and liquid water at 100 °C, (d) steam at 100 °C. Data you will need are Δ H fusion = 6.01 kJ/mol, Δ H vapn = 40.6 kJ/mol (at 100 °C), molar heat capacity of H 2 O(l) = 76 J mol –1 °C –1.

155 155 Section 10.9 Phase Diagrams Copyright © Cengage Learning. All rights reserved Return to TOC Phase Diagram for Carbon Dioxide

156 156 Section 10.9 Phase Diagrams Copyright © Cengage Learning. All rights reserved Return to TOC Phase Diagram for Water

157 157 Section 10.9 Phase Diagrams Copyright © Cengage Learning. All rights reserved Return to TOC Concept Check As intermolecular forces increase, what happens to each of the following? Why?  Boiling point  Viscosity  Surface tension  Enthalpy of fusion  Freezing point  Vapor pressure  Heat of vaporization

158 158 Section 10.9 Phase Diagrams Copyright © Cengage Learning. All rights reserved Return to TOC Chapter 10 review questions - pg m - 20 questions for reviewhttp://www.sciencegeek.net/APchemistry/APtaters/chap10rev.ht m Born-Haber Cycles 22 question quiz on phase diagrams ms.htmhttp://www.sciencegeek.net/APchemistry/APtaters/PhaseDiagra ms.htm 16 questions Phase-Energy Diagrams #2 ms2.htmhttp://www.sciencegeek.net/APchemistry/APtaters/PhaseDiagra ms2.htm


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