Answer
DIFFERENCES
VAN DER WAAL'S ATTRACTIONS
Contains (usually non metal) dipoles creating a bond
Usually weaker:
London dispersion forces have non polar dipoles and so they do not bond easily so bonding has to be induced
Dipole-Dipole interaction uses polar dipoles that attach easily but since the other non metals are more electronegative than hydrogen, the bonds with another electronegative dipole are weaker.
Can only form strong bonds with a few dipoles
Eg:
London Dispersion force: Cl2 (Diatomic Chlorine Molecule).
Dipole dipole interaction: CCl4 (Carbon tetrachloride).
HYDROGEN BONDING
Uses hydrogen (most electropositive non metal) and dipole of a different charge to create a bond.
Usually stronger:
Hydrogen is very electropositive and polar thus bonds strongly with dipoles that are relatively electronegative.
Can form strong bonds with any dipole.
Eg:
H2O (Water)
HCl (Hydrochloric Acid)
SIMILARITIES
Both are intermolecular forces.
Both occur between Dipoles.
Both depend on compounds structural geometry.
Both occur between non metal dipoles.
In case of dipole dipole interaction and hydrogen bonding, polarity is involved, in case of London dispersion forces, development of temporary partial charges is involved. Therefore both types of intermolecular bonding require partial charges.
Work Step by Step
Development of partial charges in co-valent bonds makes polar co-valent bonds. Polar co-vant bonds have stronger forces of attraction due to half charges being involved. The atoms involved in making co-valently bonded molecules are known as dipoles. The more the difference in electronegativity the greater the force of the bond between them, Hydrogen the least electronegative non metal and thus it binds best with other non metals to create the strongest bonds. Intermolecular forces between compounds with relatively more electropositive/ less electronegative dipoles are usually stronger, polarity also matters (high polarity = stronger bond)
London dispersion forces have non polar bonds and thus form weak bonds as they have no partial charge and only develop one due to the temporary movement of electrons.
Dipole- Dipole interactions are stronger as they contain interactions between polar dipoles.
Hydrogen bonding is the strongest because it contains interactions between hydrogen (most electropositive non metal) and other dipoles which are all more electronegative than hydrogen.
