Chapter 10 Liquids and Solids 1 10.1 Intermolecular Forces • Intermolecular forces – attractive forces between two molecules • Intramolecular – within a molecule 2 Dipole-Dipole Forces • Attractive forces between two polar molecules • Opposite charges will pull towards each other 3 Hydrogen Bonding • NOT an actual bond • An extreme form of dipole-dipole • H must be bonded to an F, O, or N • H is attracted to another F, O, or N 4 London Dispersion • An instantaneous polarization that creates a very weak dipole moment • Can induce a “domino effect” in surrounding molecules 5 Dipole-Induced Dipole • A polar molecule induces a dipole moment in a non-polar molecule 6 IMF strengths IMF H bonding Dipole-dipole Dipole-induced London Dispersion Energy (kJ/mol) 10-40 5-25 2-10 0.05-40 7 8 IMF affects… • State of matter • Boiling points/Melting points • Solubility • Reactions Rates • Surface tension/Capillary action 9 10.2 Liquid State • Surface tension – resistance of a liquid to an increase in its surface area 10 10.2 Liquid State • Capillary action – spontaneous rising of a liquid in a narrow tube 11 10.2 Liquid State • Viscosity – a measure of a liquid’s resistance to flow 12 10.3 An Introduction to Structures and Types of Solids • Crystalline – highly regular arrangement • Amorphous – considerable disorder 13 Crystal Structures 14 Types of Crystalline Solids • Ionic solids – made of ionic compounds • Molecular solids – made of molecules • Atomic solids – made of atoms 15 10.4 Structure & Bonding in Metals • Alloy – contains mix of elements & has metallic properties • Substitutional alloy – some metal atoms replaced by other metal atoms • Interstitial alloy – atoms go in holes 16 17 10.5 Carbon & Silicon: Network Atomic Solids • Network solids – contain strong directional covalent bonds • Carbon • Graphite • Diamond 18 Network Solids • Silicon • Silica – SiO2 • Silicates – compounds closely related to silica, found in most rocks, soils, and clay • Glass – amorphous solid formed when silica is heated & cooled rapidly 19 Semiconductors • Electrons can jump from the empty molecular orbitals in silicon but not in carbon • Carbon is an insulator • Silicon is a semiconductor • Can increase conductivity by “doping” 20 Doping Semiconductors • Doping – adding alternate atoms • n-type semiconductor – adding another element with more valence electrons • p-type semiconductor – adding another element with less valence electrons 21 10.6 Molecular Solids • Ice, CO2, I2, P4, S8 22 10.7 Ionic Solids • They form 3D crystalline lattice structures 23 10.8 Vapor Pressure & Changes of State • Vapor pressure • Clausius-Clapeyron Equation 24 Lab Calculations 25 10.8 Vapor Pressure & Changes of State • Phase changes • Vaporization/evaporization • Condensation • Sublimation • Melting (fusion) 26 Heating Curve 27 10.9 Phase Diagrams Review on your own 28