CHM 2046 Lecture Notes - Lecture 1: Viscosity, Van Der Waals Force, Capillary Action
Document Summary
Exists in 3 physical states (solids, liquids, gas) Solids have the strongest intermolecular forces between atoms. State of matter is affected by temperature change. Gas can become a liquid by not only cooling but also by increasing the pressure. Dispersion forces: present in all molecules; weakest force. Also called london forces or van der waals forces. The larger the surface area, the greater the dispersion forces and the higher the boiling point. Dipole-dipole forces: occur between polar molecules, which exhibit partial charges resulting in dipole moments. The larger the dipole moment, the higher the boiling point. Like dissolves like pentane is nonpolar, water is polar thus they do not mix. Hydrogen bond: strong, between two polar molecules; occur between a hydrogen atom and fon (fluorine, oxygen, and nitrogen, respectively) Due to the hydrogen bonding it is more difficult to break the bonds. Ion-dipole forces: occur between polar and ionic molecules.
