LESSON 1-INTERMOLECULAR FORCE

• INTERMOLECULAR FORCE


  responsible for most of the physical and chemical properties of matter
• INTERMOLECULAR FORCE 


  the attractive and repulsive forces that arise between the molecules of a substance
• the particles in a gas are in constant, random motion
• The combined volume of the particles is negligible
• The particles exert no forces on one another
• Any collisions between the particles are completely elastic
• The average kinetic energy of the particles is proportional to the temperature
• Intramolecular forces 


  are the forces that hold atoms together within a molecule
• Intermolecular forces 


  are forces that exist between molecules
• Intramolecular force


  stronger type of molecular force
• Intermolecular force


  weaker type of molecular force
• Intramolecular force


  refers to the chemical bonds that hold atoms together
• Intermolecular force


  refers to the attractive force exist between molecules
• BONDING FORCE


  Forces of attraction or repulsion which act between neighboring particles such as atoms, molecules or ions
• Ion-Dipole Forces


  When an Ion & a nearby polar molecule attract to e/other
• Dipole-Dipole Forces


  Electrostatic interactions between the permanent dipoles of different molecules
• Solvation


  A process in which an Ion is surrounded by solvent molecules.
• The higher the dipole moment, the higher the boiling point
• Hydrogen bond


  Stronger type exists between H->O, H->N, H->F
• Ion-Induced Dipole Force


  A non-polar molecule is polarized by an ion placed near it
• the bond of the molecules are directly proportional to the energy and boiling point
• Dipole-Induced Dipole Force


  non-polar molecules are transformed into induced dipoles due to the presence of a polar molecule nearby
• Dispersion (London) Force


  Weakest among all IMF and exists in non-polar molecules
• WHAT IS THE STRONGEST IMF POSSIBLE? CH3OH

  Hydrogen
• WHAT IS THE STRONGEST IMF POSSIBLE? CCl4

  London
• WHAT IS THE STRONGEST IMF POSSIBLE? Cl2

  London
• WHAT IS THE STRONGEST IMF POSSIBLE? CH3Br

  Dipole-Dipole
• WHAT IS THE STRONGEST IMF POSSIBLE? CH3CH3

  London
• WHAT IS THE STRONGEST IMF POSSIBLE? NH3

  Hydrogen
• Evaluate the Strongest IMF & Boiling Point? MgCl2 or PCl3

  MgCl2 -> London -> Higher Boiling Point

  PCl3 -> Dipole-Dipole
• Evaluate the Strongest IMF & Boiling Point? CH3NH2 or CH3F

  CH3NH2 -> Hydrogen-> Higher Boiling Point

  CH3F -> Dipole-Dipole
• Evaluate the Strongest IMF & Boiling Point? CH3OH or CH3CH2OH

  CH3CH2OH -> Hydrogen -> Higher Boiling Point

  CH3OH -> Hydrogen