Intermolecular forces

Van der waals-the weakest intermolecular force
1. temporary dipole
2. can occur in all kind of molecules
3. work in addition to other intermolecular forces
4. dipole moments are formed by the changing position of an electron cloud. the larger the molecule, the greater the force.
Dipole-dipole_weaker than hydrogen but stronger than van der waals
1. permanent dipole
2. occurs in polar molecules
3. all the polar bonds in a molecule add up to give an uneven charge distribution across the whole molecule. Dipole moments depend on the 3D shape of the molecule.
4. eg. Trichloromethane, HCl, Hydrogen sulfide.
Hydrogen- strongest intermolecular force
1. occurs in molecules in which a hydrogen atom is bonded to either flourine, oxygen or nitrogen.
2. molecules are needed to have atleast one lone pair of electrons
3. when any of flourine, oxygen or nitrogen bond to hydrogen a very strong dipole forms were hydrogen has a partially positive charge and the other atom has a strong negative charge.
4. eg. HF, H2O, NH3

Resource summary

	Created by Irene Binil about 7 years ago