AP* Chapter 10. Liquids and Solids. Friday, November 22, 13

AP* Chapter 10 Liquids and Solids

AP Learning Objectives LO 1.11 The student can analyze data, based on periodicity and the properties of binary compounds, to identify patterns and generate hypotheses related to the molecular design of compounds for which data are not supplied. (Sec 10.1) LO 2.1 Students can predict properties of substances based on their chemical formulas, and provide explanations of their properties based on particle views. (Sec 10.1-10.8) LO 2.3 The student is able to use aspects of particular models (i.e. particle spacing, motion, and forces of attraction) to reason about observed differences between solid and liquid phases and among solid and liquid materials. (Sec 10.1-10.7) LO 2.11 The student is able to explain the trends in properties and/or predict properties of samples consistently of particles with no permanent dipole on the basis of London dispersion forces. (Sec 10.1) LO 2.13 The student is able to describe the relationships between the structural features of polar molecules and the forces of

AP Learning Objectives LO 2.16 The student is able to explain the properties (phase, vapor pressure, viscosity, etc.) of small and large molecular compounds in terms of the strengths and types of intermolecular forces. (Sec 10.1-10.7) LO 2.19 The student can create visual representations of ionic substances that connect the microscopic structure to macroscopic properties, and/or use representations to connect the microscopic structure to macroscopic properties (e.g. boiling point, solubility, hardness, brittleness, low volatility, lack of malleability, ductility, or conductivity). (Sec 10.3-10.4, 10.8) LO 2.20 The student is able to explain how a bonding model involving delocalized electrons is consistent with macroscopic properties of metal (e.g. conductivity, malleability, ductility, and low volatility) and the shell model of the atom. (Sec 10.4) LO 2.22 The student is able to design or evaluate a plan to collect and/or interpret data needed to deduce the type of bonding in a sample of a solid. (Sec 10.3-10.7)

AP Learning Objectives LO 2.23 The student can create a representation of an ionic solid that shows essential characteristics of the structure and interactions present in the substance. (Sec 10.7) LO 2.24 The student is able to explain a representation that connects properties of an ionic solid to its structural attributes and to the interactions present at the atomic level. (Sec 10.7) LO 2.25 The student is able to compare the properties of metal alloys with their constituent elements to determine if an alloy has formed, identify the type of alloy formed, and explain the differences in properties using particulate level reasoning. (Sec 10.4) LO 2.26 Students can use the electron sea model of metallic bonding to predict or make claims about the macroscopic properties of metals or alloys. (Sec 10.4) LO 2.27 The student can create a representation of a metallic solid that shows essential characteristics of the structure and

AP Learning Objectives LO 2.28 The student is able to explain a representation that connects properties of a metallic solid to its structural attributes and to the interactions present at the atomic level. (Sec 10.4) LO 2.29 The student can create a representation of a covalent solid that shows essential characteristics of the structure and interactions present in the substance. (Sec 10.5) LO 2.30 The student is able to explain a representation that connects properties of a covalent solid to its structural attributes and to the interactions present at the atomic level. (Sec 10.5) LO 2.31 The student can create a representation of a molecular solid that shows essential characteristics of the structure and interactions present in the substance. (Sec 10.3, 10.6) LO 2.32 The student is able to explain a representation that connects properties of a molecular solid to its structure attributes and to the interactions present at the atomic level. (Sec 10.6)

AP Learning Objectives LO 5.6 The student is able to use calculations or estimations to relate energy changes associated with heating/cooling a substance to the heat capacity, relate energy changes associated with a phase transition to the enthalpy of fusion/vaporization, relate energy changes associated with chemical reaction to the enthalpy of the reaction, and relate energy changes to PΔV work. (Sec 10.8) LO 5.9 The student is able to make claims and/or predictions regarding relative magnitudes of the forces acting within collections of interacting molecules based on the distribution of electrons within the molecules and the type of intermolecular forces through which the molecules interact. (Sec 10.1-10.7) LO 5.10 The student can support the claim about whether a process is a chemical or physical change (or may be classified as both) based on whether the process involves changes in intramolecular versus intermolecular interactions. (Sec 10.8) LO 5.11 The student is able to identify the noncovalent interactions within and between large molecules, and/or connect

Section 10.1 Intermolecular Forces AP Learning Objectives, Margin Notes and References Learning Objectives LO 1.11 The student can analyze data, based on periodicity and the properties of binary compounds, to identify patterns and generate hypotheses related to the molecular design of compounds for which data are not supplied. LO 2.1 Students can predict properties of substances based on their chemical formulas, and provide explanations of their properties based on particle views. LO 2.3 The student is able to use aspects of particular models (i.e. particle spacing, motion, and forces of attraction) to reason about observed differences between solid and liquid phases and among solid and liquid materials. LO 2.11 The student is able to explain the trends in properties and/or predict properties of samples consistently of particles with no permanent dipole on the basis of London dispersion forces. LO 2.13 The student is able to describe the relationships between the structural features of polar molecules and the forces of attraction between the particles. LO 2.16 The student is able to explain the properties (phase, vapor pressure, viscosity, etc.) of small and large molecular compounds in terms of the strengths and types of intermolecular forces.

Section 10.1 Intermolecular Forces AP Learning Objectives, Margin Notes and References AP Margin Notes Appendix 7.3 Intermolecular Forces: The Difference Between Real and Ideal Gases Appendix 7.5 Intermolecular Forces Between Polar and Nonpolar Molecules The relationship of the physical and chemical processes of a substance to its bonding characteristics is discussed in Appendix 7.6 Distinguishing Between Chemical and Physical Changes at the Molecular Level. Additional AP References LO 1.11 (see Appendix 7.6, Distinguishing Between Chemical and Physical Changes at the Molecular Level. ) LO 2.11 (see Appendix 7.5, Intermolecular Forces Between Polar and Nonpolar Molecules ) LO 2.13 (see Appendix 7.3, Intermolecular Forces: The Difference Between Real and Ideal Gases ) LO 2.13 (see Appendix 7.5, Intermolecular Forces Between Polar and Nonpolar Molecules )

Section 10.1 Intermolecular Forces Intermolecular Forces Forces that occur between molecules. Dipole dipole forces Hydrogen bonding London dispersion forces Intramolecular bonds are stronger than intermolecular forces. Copyright Cengage Learning. All rights reserved 10

Section 10.1 Intermolecular Forces Hydrogen Bonding in Water Blue dotted lines are the intermolecular forces between the water molecules.

Section 10.1 Intermolecular Forces 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. Copyright Cengage Learning. All rights reserved 13

Section 10.1 Intermolecular Forces 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. Copyright Cengage Learning. All rights reserved 15

Section 10.1 Intermolecular Forces 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. Copyright Cengage Learning. All rights reserved 17

Section 10.1 Intermolecular Forces Dipole-Dipole Forces To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERE Copyright Cengage Learning. All rights reserved 18

Section 10.1 Intermolecular Forces Hydrogen Bonding To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERE Copyright Cengage Learning. All rights reserved 19

Section 10.1 Intermolecular Forces Hydrogen Bonding Strong dipole-dipole forces. Hydrogen is bound to a highly electronegative atom nitrogen, oxygen, or fluorine. That same hydrogen is then electrostatically attracted to a lone pair on the nitrogen, oxygen or fluorine on adjacent molecules. Copyright Cengage Learning. All rights reserved 20

Section 10.1 Intermolecular Forces London Dispersion Forces To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERE Copyright Cengage Learning. All rights reserved 21

Section 10.1 Intermolecular Forces 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. Copyright Cengage Learning. All rights reserved 22

Section 10.1 Intermolecular Forces Melting and Boiling Points In general, the stronger the intermolecular forces, the higher the melting and boiling points. Copyright Cengage Learning. All rights reserved 23

Section 10.1 Intermolecular Forces CONCEPT CHECK! Draw two Lewis structures for the formula C 2 H 6 O and compare the boiling points of the two molecules. Copyright Cengage Learning. All rights reserved 26

Section 10.2 The Liquid State AP Learning Objectives, Margin Notes and References Learning Objectives LO 2.1 Students can predict properties of substances based on their chemical formulas, and provide explanations of their properties based on particle views. LO 2.3 The student is able to use aspects of particular models (i.e. particle spacing, motion, and forces of attraction) to reason about observed differences between solid and liquid phases and among solid and liquid materials. LO 2.16 The student is able to explain the properties (phase, vapor pressure, viscosity, etc.) of small and large molecular compounds in terms of the strengths and types of intermolecular forces. LO 5.9 The student is able to make claims and/or predictions regarding relative magnitudes of the forces acting within collections of interacting molecules based on the distribution of electrons within the molecules and the type of intermolecular forces through which the molecules interact.

Section 10.2 The Liquid State 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. Copyright Cengage Learning. All rights reserved 29

Section 10.2 The Liquid State 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. Copyright Cengage Learning. All rights reserved 30

Section 10.2 The Liquid State Convex Meniscus Formed by Nonpolar Liquid Mercury Which force dominates alongside the glass tube cohesive or adhesive forces? Copyright Cengage Learning. All rights reserved 31

Section 10.2 The Liquid State Convex Meniscus Formed by Nonpolar Liquid Mercury Which force dominates alongside the glass tube cohesive or adhesive forces? cohesive forces Copyright Cengage Learning. All rights reserved 31

Section 10.2 The Liquid State Liquids Viscosity measure of a liquid s resistance to flow: Liquids with large intermolecular forces or molecular complexity tend to be highly viscous. Copyright Cengage Learning. All rights reserved 33

Section 10.3 An Introduction to Structures and Types of Solids AP Learning Objectives, Margin Notes and References Learning Objectives LO 2.1 Students can predict properties of substances based on their chemical formulas, and provide explanations of their properties based on particle views. LO 2.3 The student is able to use aspects of particular models (i.e. particle spacing, motion, and forces of attraction) to reason about observed differences between solid and liquid phases and among solid and liquid materials. LO 2.16 The student is able to explain the properties (phase, vapor pressure, viscosity, etc.) of small and large molecular compounds in terms of the strengths and types of intermolecular forces. LO 2.19 The student can create visual representations of ionic substances that connect the microscopic structure to macroscopic properties, and/or use representations to connect the microscopic structure to macroscopic properties (e.g. boiling point, solubility, hardness, brittleness, low volatility, lack of malleability, ductility, or conductivity). LO 2.22 The student is able to design or evaluate a plan to collect and/or interpret data needed to deduce the type of bonding in a sample of a solid. LO 2.31 The student can create a representation of a molecular solid that shows essential characteristics of the structure and interactions present in the substance.

Section 10.3 An Introduction to Structures and Types of Solids AP Learning Objectives, Margin Notes and References Additional AP References LO 2.22 (see APEC #6, Intermolecular Forces. )

Section 10.3 An Introduction to Structures and Types of Solids Solids Amorphous Solids: Disorder in the structures Glass Crystalline Solids: Ordered Structures Unit Cells Copyright Cengage Learning. All rights reserved 36

Section 10.3 An Introduction to Structures and Types of Solids 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 Copyright Cengage Learning. All rights reserved 38

Section 10.3 An Introduction to Structures and Types of Solids 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. Copyright Cengage Learning. All rights reserved 40

Section 10.4 Structure and Bonding in Metals AP Learning Objectives, Margin Notes and References Learning Objectives LO 2.1 Students can predict properties of substances based on their chemical formulas, and provide explanations of their properties based on particle views. LO 2.3 The student is able to use aspects of particular models (i.e. particle spacing, motion, and forces of attraction) to reason about observed differences between solid and liquid phases and among solid and liquid materials. LO 2.16 The student is able to explain the properties (phase, vapor pressure, viscosity, etc.) of small and large molecular compounds in terms of the strengths and types of intermolecular forces. LO 2.19 The student can create visual representations of ionic substances that connect the microscopic structure to macroscopic properties, and/or use representations to connect the microscopic structure to macroscopic properties (e.g. boiling point, solubility, hardness, brittleness, low volatility, lack of malleability, ductility, or conductivity). LO 2.20 The student is able to explain how a bonding model involving delocalized electrons is consistent with macroscopic properties of metal (e.g. conductivity, malleability, ductility, and low volatility) and the shell model of the atom. LO 2.22 The student is able to design or evaluate a plan to collect and/or interpret data needed to deduce the type of bonding in a sample of a solid.

Section 10.4 Structure and Bonding in Metals AP Learning Objectives, Margin Notes and References Learning Objectives LO 2.25 The student is able to compare the properties of metal alloys with their constituent elements to determine if an alloy has formed, identify the type of alloy formed, and explain the differences in properties using particulate level reasoning. LO 2.26 Students can use the electron sea model of metallic bonding to predict or make claims about the macroscopic properties of metals or alloys. LO 2.27 The student can create a representation of a metallic solid that shows essential characteristics of the structure and interactions present in the substance. LO 2.28 The student is able to explain a representation that connects properties of a metallic solid to its structural attributes and to the interactions present at the atomic level. LO 5.9 The student is able to make claims and/or predictions regarding relative magnitudes of the forces acting within collections of interacting molecules based on the distribution of electrons within the molecules and the type of intermolecular forces through which the molecules interact. Additional AP References LO 2.22 (see APEC #6, Intermolecular Forces. )

Section 10.4 Structure and Bonding in Metals Closest Packing Model Closest Packing: Assumes that metal atoms are uniform, hard spheres. Spheres are packed in layers. Copyright Cengage Learning. All rights reserved 45

Section 10.4 Structure and Bonding in Metals The Closest Packing Arrangement of Uniform Spheres abab 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. Copyright Cengage Learning. All rights reserved 46

Section 10.4 Structure and Bonding in Metals The Closest Packing Arrangement of Uniform Spheres abca 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. Copyright Cengage Learning. All rights reserved 47

Section 10.4 Structure and Bonding in Metals The Indicated Sphere Has 12 Nearest Neighbors Each sphere in both ccp and hcp has 12 equivalent nearest neighbors. Copyright Cengage Learning. All rights reserved 50

Section 10.4 Structure and Bonding in Metals CONCEPT CHECK! Determine the number of metal atoms in a unit cell if the packing is: a) Simple cubic b) Cubic closest packing Copyright Cengage Learning. All rights reserved 52

Section 10.4 Structure and Bonding in Metals 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 Copyright Cengage Learning. All rights reserved 52

Section 10.4 Structure and Bonding in Metals 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. Copyright Cengage Learning. All rights reserved 53

Section 10.4 Structure and Bonding in Metals CONCEPT CHECK! Silver metal crystallizes in a cubic closest packed structure. The face centered cubic unit cell edge is 409 pm. Copyright Cengage Learning. All rights reserved 54

Section 10.4 Structure and Bonding in Metals 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. Copyright Cengage Learning. All rights reserved 54

Section 10.4 Structure and Bonding in Metals The Electron Sea Model A regular array of cations in a sea of mobile valence electrons.

Section 10.4 Structure and Bonding in Metals Band or Molecular Orbital (MO) Model Electrons are assumed to travel around the metal crystal in molecular orbitals formed from the valence atomic orbitals of the metal atoms. Copyright Cengage Learning. All rights reserved 57

Section 10.4 Structure and Bonding in Metals 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. Copyright Cengage Learning. All rights reserved 60

Section 10.5 Carbon and Silicon: Network Atomic Solids AP Learning Objectives, Margin Notes and References Learning Objectives LO 2.1 Students can predict properties of substances based on their chemical formulas, and provide explanations of their properties based on particle views. LO 2.3 The student is able to use aspects of particular models (i.e. particle spacing, motion, and forces of attraction) to reason about observed differences between solid and liquid phases and among solid and liquid materials. LO 2.16 The student is able to explain the properties (phase, vapor pressure, viscosity, etc.) of small and large molecular compounds in terms of the strengths and types of intermolecular forces. LO 2.22 The student is able to design or evaluate a plan to collect and/or interpret data needed to deduce the type of bonding in a sample of a solid. LO 2.29 The student can create a representation of a covalent solid that shows essential characteristics of the structure and interactions present in the substance. LO 2.30 The student is able to explain a representation that connects properties of a covalent solid to its structural attributes and to the interactions present at the atomic level. LO 5.9 The student is able to make claims and/or predictions regarding relative magnitudes of the forces acting within collections of interacting molecules based on the distribution of

Section 10.5 Carbon and Silicon: Network Atomic Solids AP Learning Objectives, Margin Notes and References Additional AP References LO 2.22 (see APEC #6, Intermolecular Forces. )

Section 10.5 Carbon and Silicon: Network Atomic Solids Network Solids To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERE Copyright Cengage Learning. All rights reserved 64

Section 10.5 Carbon and Silicon: Network Atomic Solids 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. Copyright Cengage Learning. All rights reserved 68

Section 10.5 Carbon and Silicon: Network Atomic Solids 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. Copyright Cengage Learning. All rights reserved 69

Section 10.5 Carbon and Silicon: Network Atomic Solids Silicon Crystal Doped with (a) Arsenic and (b) Boron

Section 10.6 Molecular Solids AP Learning Objectives, Margin Notes and References Learning Objectives LO 2.1 Students can predict properties of substances based on their chemical formulas, and provide explanations of their properties based on particle views. LO 2.3 The student is able to use aspects of particular models (i.e. particle spacing, motion, and forces of attraction) to reason about observed differences between solid and liquid phases and among solid and liquid materials. LO 2.16 The student is able to explain the properties (phase, vapor pressure, viscosity, etc.) of small and large molecular compounds in terms of the strengths and types of intermolecular forces. LO 2.22 The student is able to design or evaluate a plan to collect and/or interpret data needed to deduce the type of bonding in a sample of a solid. LO 2.31 The student can create a representation of a molecular solid that shows essential characteristics of the structure and interactions present in the substance. LO 2.32 The student is able to explain a representation that connects properties of a molecular solid to its structure attributes and to the interactions present at the atomic level. LO 5.9 The student is able to make claims and/or predictions regarding relative magnitudes of the forces acting within collections of interacting molecules based on the distribution of

Section 10.6 Molecular Solids AP Learning Objectives, Margin Notes and References Additional AP References LO 2.22 (see APEC #6, Intermolecular Forces. )

Section 10.6 Molecular Solids To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERE Copyright Cengage Learning. All rights reserved 74

Section 10.7 Ionic Solids AP Learning Objectives, Margin Notes and References Learning Objectives LO 2.1 Students can predict properties of substances based on their chemical formulas, and provide explanations of their properties based on particle views. LO 2.3 The student is able to use aspects of particular models (i.e. particle spacing, motion, and forces of attraction) to reason about observed differences between solid and liquid phases and among solid and liquid materials. LO 2.16 The student is able to explain the properties (phase, vapor pressure, viscosity, etc.) of small and large molecular compounds in terms of the strengths and types of intermolecular forces. LO 2.22 The student is able to design or evaluate a plan to collect and/or interpret data needed to deduce the type of bonding in a sample of a solid. LO 2.23 The student can create a representation of an ionic solid that shows essential characteristics of the structure and interactions present in the substance. LO 2.24 The student is able to explain a representation that connects properties of an ionic solid to its structural attributes and to the interactions present at the atomic level. LO 5.9 The student is able to make claims and/or predictions regarding relative magnitudes of the forces acting within collections of interacting molecules based on the distribution of

Section 10.7 Ionic Solids AP Learning Objectives, Margin Notes and References Additional AP References LO 2.22 (see APEC #6, Intermolecular Forces. )

Section 10.7 Ionic Solids To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERE Copyright Cengage Learning. All rights reserved 77

Section 10.7 Ionic Solids Ionic Solids Ionic solids are stable, high melting substances held together by the strong electrostatic forces that exist between oppositely charged ions. Copyright Cengage Learning. All rights reserved 78

Section 10.7 Ionic Solids 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. Copyright Cengage Learning. All rights reserved 80

Section 10.7 Ionic Solids 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. Copyright Cengage Learning. All rights reserved 81

Section 10.8 Vapor Pressure and Changes of State AP Learning Objectives, Margin Notes and References Learning Objectives LO 2.1 Students can predict properties of substances based on their chemical formulas, and provide explanations of their properties based on particle views. LO 2.19 The student can create visual representations of ionic substances that connect the microscopic structure to macroscopic properties, and/or use representations to connect the microscopic structure to macroscopic properties (e.g. boiling point, solubility, hardness, brittleness, low volatility, lack of malleability, ductility, or conductivity). LO 5.6 The student is able to use calculations or estimations to relate energy changes associated with heating/cooling a substance to the heat capacity, relate energy changes associated with a phase transition to the enthalpy of fusion/vaporization, relate energy changes associated with chemical reaction to the enthalpy of the reaction, and relate energy changes to PΔV work. LO 5.10 The student can support the claim about whether a process is a chemical or physical change (or may be classified as both) based on whether the process involves changes in intramolecular versus intermolecular interactions.

Section 10.8 Vapor Pressure and Changes of State 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. Copyright Cengage Learning. All rights reserved 87

Section 10.8 Vapor Pressure and Changes of State Vapor Pressure Liquids in which the intermolecular forces are large have relatively low vapor pressures. Vapor pressure increases significantly with temperature. Copyright Cengage Learning. All rights reserved 90

Section 10.8 Vapor Pressure and Changes of State Clausius Clapeyron Equation P vap = vapor pressure ΔH vap = enthalpy of vaporization R = 8.3145 J/K mol Copyright Cengage Learning. All rights reserved 92

Section 10.8 Vapor Pressure and Changes of State 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. Copyright Cengage Learning. All rights reserved 93

Section 10.8 Vapor Pressure and Changes of State Changes of State To play movie you must be in Slide Show Mode PC Users: Please wait for content to load, then click to play Mac Users: CLICK HERE Copyright Cengage Learning. All rights reserved 94

Section 10.8 Vapor Pressure and Changes of State CONCEPT CHECK! Which would you predict should be larger for a given substance: ΔH vap or ΔH fus? Explain why. Copyright Cengage Learning. All rights reserved 96

Section 10.9 Phase Diagrams A convenient way of representing the phases of a substance as a function of temperature and pressure: Triple point Critical point Phase equilibrium lines Copyright Cengage Learning. All rights reserved 97

Section 10.9 Phase Diagrams 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