intermolecular forces

• What are intermolecular forces?

  Forces between molecules
• What is the difference between intermolecular forces and covalent bonds?

  Intermolecular forces attract molecules, covalent bonds connect atoms
• What is the first type of intermolecular force mentioned?

  Van der Waals forces
• How are van der Waals forces also known?

  London forces
• Why do electrons create a temporary dipole in an atom?

  Electrons are not evenly distributed
• What is a temporary dipole?

  A short-lived positive and negative end in a molecule
• How do temporary dipoles lead to molecular attraction?

  They create short-term positive and negative attractions
• What type of dipole do some molecules have permanently?

  Permanent dipole
• How do permanent dipoles attract each other?

  Positive end attracts negative end of another molecule
• What is an example of a molecule with a permanent dipole?

  Hydrogen chloride
• What type of attraction occurs between molecules with permanent dipoles?

  Permanent dipole-dipole attraction
• What is a special case of permanent dipole-dipole attraction?

  Hydrogen bond
• When does a hydrogen bond occur?

  When hydrogen is bonded with fluorine, oxygen, or nitrogen
• Why are hydrogen bonds significant for water?

  They keep water liquid at room temperature
• How does the strength of hydrogen bonds compare to covalent bonds?

  Hydrogen bonds are weaker than covalent bonds
• What is the strength of hydrogen bonds compared to covalent bonds?

  Hydrogen bonds are about 10 times weaker
• How strong are other permanent dipole-dipole bonds compared to covalent bonds?

  They are about 5 times weaker
• How strong are van der Waals forces compared to covalent bonds?

  They are about 100 times weaker
• What are the three types of bonding between molecules?

  1. Van der Waals forces
  2. Permanent dipole-dipole attractions
  3. Hydrogen bonds
• How do the strengths of intermolecular forces compare to covalent bonds?

  • Covalent bonds: strength of 100
  • Hydrogen bonds: strength of about 10
  • Permanent dipole-dipole: strength of about 5
  • Van der Waals forces: strength of about 1