Intermolecular Forces of Attraction

There are three intermolecular forces of attraction: London dispersion, dipole dipole, and Hydrogen bonding. When a N2H4 molecule is near another N2H4 molecule, all three intermolecular forces of attraction occur between the two molecules.

London dispersion: a weak force of attraction between any 2 molecules (polar or nonpolar) that is created by temporary dipoles. These temporary dipoles are caused by the movement of electrons around both molecules.

Since London dispersion occurs between all molecules, an N2H4 molecule is attracted by the London dispersion force to another N2H4 molecule.

Dipole Dipole: an electrostatic attraction caused by the positive end of one dipole (a polar molecule) being attracted to the negative end of another dipole.

N2H4 is a polar molecule, there will be an dipole dipole attraction between two N2H4 molecules. The negative end of one N2H4, which is the end with nitrogen’s unshared electron pair, is attracted to the positive end of the other N2H4, which is the end with a hydrogen atom.

The Dipole Dipole force of attraction is shown in red by the dashed line between the positive end of one N2H4 molecule and the negative end of the other N2H4 molecule.

Hydrogen bonding: a special case of dipole dipole attraction. In hydrogen bonding, a temporary covalent bond forms between the hydrogen (H) of one molecule and the Oyxgen (O), Nitrogen (N) or Flourine (F) of an adjacent molecule.

Two molecules of N2H4 will have hydrogen bonding between them. The hydrogen atom in one molecule of N2H4 will form a temporary covalent bond with the Nitrogen of an adjacent N2H4 molecule. 

The temporary covalent bond that occurs in hydrogen bonding between two N2H4 molecule, shown in red with a  solid line between the Hydrogen of one N2H4 molecule the Nitrogen of the adjacent N2H4 molecule.