Question

How do dipole dipole forces differ from hydrogen bonds?

Answer 1

Dipole dipole forces and hydrogen bonds are observed in polar compounds. Both the forces are intermolecular forces. The hydrogen bond is observed between the water molecules.

Complete step by step answer:
The dipole- dipole forces are the attractive forces which are formed between the positive end of the one polar molecule and the negative end of the polar molecule. From this statement it is clear that the dipole –dipole forces are intermolecular forces which occur between the two polar compounds. The polar compounds are those which have partial negative charge and partial positive charge. The strength of dipole –dipole forces ranges from 5KJ to 20KJ per mole. The dipole-dipole forces are much weaker bonds as compared to the ionic bond or the covalent bond. They have significant effect only when the molecules are close to each other. As the polar molecule has a partial negative end and a partial positive end, the partially positive end of the polar molecule will attract the partially negative end of the other molecule.
Example: In an ICI molecule, the chlorine atom is more electronegative in nature than the iodine atom so the chlorine will bear partial negative charge and the iodine will have partial positive charge. So the partially positive iodine of one molecule will attract the partially negative chlorine of another molecule.
The hydrogen bonds are the intermolecular forces which are the special type of dipole –dipole attraction. In the hydrogen bond, the hydrogen atom is bonded to a strong electronegative atom which exists in the vicinity of another electronegative atom having a lone pair of electrons. The hydrogen bonds are stronger than the dipole-dipole forces and dispersion forces but they are weaker than the covalent and ionic bonds.
Example: Hydrogen bonding can be seen between the molecules of water, where the hydrogen atom of one water molecule is bonded to electronegative atom oxygen to another water molecule.

Note:
Don’t get confused between intermolecular forces and intramolecular forces as intermolecular forces are formed between two different molecules and the intramolecular forces are formed within a molecule.