Intermolecular Forces

Intramolecular bonds are the bonds within the molecule (Covalent bonds)

Intermolecular forces are the forces of attraction between molecules due to polarity and movement of electrons within the bond.

The more polar the molecule, the stronger the intermolecular force.

Intermolecular forces are weaker than ionic or covalent bonds.

The strength of the intermolecular force determines the phase (solid, liquid, or gas) that the molecules have.

Strong forces: solid phase

Weak forces: gas phase

The larger the polarity of the molecule, the stronger the intermolecular force between molecules.

Three types of intermolecular forces:

• London-Dispersion: Weakest

  • Between 2 non-polar

    • I.e Cl2, O2, F2

  • All molecules (both P and NP) have some type of Londin Dispersion.

• Dipole-Dipole forces: Middle

  • Between 2 polar molecules

  • The larger in size of the polar molecule, the weaker the dipole force because the molecules can’t get as close to each other.

• Hydrogen bond: Strongest

  • Anything with Hydrogen will be a hydrogen bond.