REVIEWER

• Intermolecular Attraction


  Exist between molecules; opposite charges molecule-molecule
• Intramolecular Attraction


  Forces within molecules; Covalent/Ionic bonding; element-element
• Liquid


  • Strong intermolecular; more dense & less compressible
• Solid


  • Stronger IMF; not very compressible; rigid; compact
• Gas


  • Disordered; highly compressible; does not have definite shape
• Factors affecting the state of a substance

  • Temperature
  • Pressure - more pressure = particles are closer together
• Covalent


  Sharing of electrons; 2 non-metals
• Kinetic energy


  Keeps the molecules apart & move around; more motion = high kinetic energy & vice versa
• IMF


  Try to draw the particles together
• Model used to explain the behavior of matter

  1. Constantly in motion; kinetic energy

  2. Directly proportional to its temperature

  3. Space between particles

  4. When the temperature of the substance changes sufficiently

  5. Attractive forces in between particles called intermolecular forces
• Polar Covalent Forces


  • Unequal sharing of electrons
• Polar Covalent Forces

  • Hydrogen Bonds - positive (Hydrogen) attraction to negative Oxygen, Nitrogen, etc.; strongest
  • Dipole-Dipole Forces - 2 ends; opposite charge
  • Ion-dipole Forces - 1 cation/anion and 1 dipole
• Nonpolar Covalent Forces

  • London Dispersion Forces - random motions; only the atom 1 is induced (influences the other dipole); temporary
  • Van Der Waals - weaker; both are induced
• Adhesion

  Different molecules attract each other
• Cohesion


  Same molecules attract each other
• Surface Tension

  • Occurs because of adhesive forces; resist external force; water droplets are rounded because of surface tension
  • High Viscosity = Strong IMF (Ex. Honey)
  • Low Viscosity = Weaker IMF (Ex. Water)
• Surface Tension


  • Walking on water
  • Floating a needle
  • Clinical test for jaundice
  • Surface tension disinfectants
  • Soaps & detergents
  • Washing with cold water
  • Why bubbles are round
  • Surface tension & droplets of water
• Viscosity


  Quantity that fluid resistance to flow
• Kinematic Viscosity


  A measure of a fluid’s internal resistance to flow under gravitational force
• Capillarity


  1. Rise of a liquid in a small passage

  2. The narrower the tube, the higher the liquid will rise
• Vapor Pressure

  • Pressure exerted by a gas/vapor; In a closed system
  • Equilibrium - equal/balance
  • Volatile - substance with high Vapor pressure at normal temp.
  • High temperature = High Vapor Pressure
• Boiling Point


  • Temperature at which vapor pressure equals the surrounding pressure
  • Higher Altitude = Lower the Pressure; Lower Altitude = Higher the Pressure
  • Higher the Temperature = Higher the Pressure
  • Normal Boiling Point - vapor pressure is
• High temperature equals high vapor pressure
• Boiling point is the temperature at which vapor pressure equals the surrounding pressure
• Higher Altitude


  Lower the Pressure
• Lower Altitude

  Higher the Pressure
• Higher the Temperature


  Higher the Pressure
• Normal Boiling Point – vapor pressure is equal to one temperature (1 atm)
• Molar Heat of Vaporization


  Energy needed to convert liquid to gas
• Vaporization (not liquid or gas) – energy stays the same; only temperature changes
• Covalent bonding in water molecule

  Between Hydrogen & Oxygen atoms
• Water molecule charge

  Carries no net electric charge, its 8 electrons are not distributed uniformly
• Properties of Solids

  • Conductivity
  • Malleability
  • Density
  • Bonding
  • Structure
• Electrical Conductivity

  A flow of electrons from one place to another
• Electrical Insulators


  • Materials that do not conduct electricity
• Heat Insulators


  • Materials with low heat conductivity
• Malleability


  Ability to hammer a solid into a sheet without breaking
• Ductility


  Refers to whether a solid can be stretched to form a wire
• Melting Points of Solids

  • Mercury -38°C
  • Tungsten 3433°C
  • Tridymite 1670°C
  • Graphite 4489°C
  • Sodium Chloride 801°C
  • Lithium Bromide 552°C
• Solubility


  A solid dissolves in a particular solvent