CHM 113 Lecture Notes - Lecture 21: Intermolecular Force, Electronegativity, Viscosity
Document Summary
Dipole dipole forces act with pure substance or mixtures. Usually dipole dipole interactions are stronger than dispersion forces. If one molecule is bigger than another then dispersion forces is stronger: hydrogen bonding. H is covalently bonded to a small, highly electronegative element in a molecule. Small, highly electronegative element with one or more unshared electron pairs in the other molecule. Acts on small molecules, but matins structures of macromolecules. Critical to structure of dna: ion dipole forces. Makes it possible for ionic substances to dissolve in polar solvents: comparing intermolecular forces. Types and strength of attractions can affect properties of a substance. Proportional to size and strength of intermolecular forces. Amount of energy required to increase the surface area b a given amount. Molecules on surface is more tightly packed. Competing forces: between liquids, between liquid and surface of glass.
