intermolecular forces

• Chemical structures and physical properties

  • Physical properties are properties that a substance displays w/o changing its chemical composition
  • depend on chemical structure
  • Chemical structure determines the type of bonding (ionic or metallic or covalent) and intermolecular forces
• Molecular Picture of Ideal gases

  • Atoms in a molecule are held together by covalent bonds
  • intramolecular forces
  • if atom/molecules have no attractive forces holding together molecules have complete freedom to spread out and take up all space in vessel containing it
• Condensed states

  • if atoms/molecules have no intermolecular forces holding them together
  • molecules have complete freedom to spread out and take up all space in vessel containing it
  • intermolecular forces result in the existence of condensed states: liquid, solid
• States of Matter

  • different states exist due to difference in freedom of movement of particles
  • Gas: complete freedom
  • liquid: slide over each other
  • solid: vibrate in fixed positions
  • the density of the state of a chemical decreases in order of gas, liquid, solid
  • the case of water is an exceptionL density of ice is lower than density of liquid water
• compressibility

  • condensed states can not be compressed
  • definite volumes
  • gas state: molecules widely spaced, highly compressible
  • liquid state: molecules are closely separated, not compressible