Intra and Intermolecular Forces

Question 1

Intramolecular forces:

Answer 1

• the forces within a molecule
• essentially Ionic and Covalent Bonds
• powerful forces

Question 2

Intermolecular forces:

Answer 2

• forces of attraction between molecules
• generally weak
• 3 types:
  1. Van der Waal’s Forces
  2. Dipole-Dipole Forces
  3. Hydrogen Bonding

Question 3

Dipole

Answer 3

• charge caused by the separation of the centers of positive and negative charge within an atom or molecule
• difference in electronegativity is between 0.4 and 1.7

Question 4

Van der Waal’s Forces

Answer 4

• weak
• caused by the random movement of electrons
• result in temporary dipoles
• occurs between non-polar molecule
• low melting and boiling points
• found between plates of graphite
• larger molecule = more temporary dipoles = more Van der Waal’s forces

Question 5

Dipole-Dipole Forces

Answer 5

• delta positive of a polar molecule attracts delta negative of another
• higher melting and boiling points
• stronger than Van der Waal’s forces because they exist between permanent dipoles while Van der Waal’s exist between temporary dipoles

Question 6

Hydrogen Bonding

Answer 6

• a special type of dipole-dipole bonding
• when hydrogen is bonded to a more electronegative element such as fluorine, nitrogen, and oxygen
• the attraction found between a delta positive hydrogen and another delta negative electronegative element
• found between water molecules/ where there is a large degree of polarity in small molecules
• causes much higher boiling points

Question 7

Van der Waal’s, Dipole-Dipole and Hydrogen Bonding in terms of power

Answer 7

Van der Waal’s < Dipole-Dipole < Hydrogen Bonding