CHEM 202 Lecture Notes - Lecture 3: Covalent Bond, Electronegativity, Vsepr Theory
Document Summary
We"ll start off by introducing all the intermolecular forces here. Involves h and o, n, and f bonds usually dipole dipole: not quite as strong as ion-dipole since on partial charges are present. Ion/dipole induced dipoles: certain functional groups can polarize neighboring molecules, thus inducing a dipole. polarizability increases with radii (electrons farther away from nucleus is easier to polarize!) decreases across period, increases down group (chap 39) Dispersive forces weakest of the intermolecular forces, involves london forces associated with non-polar interactions. These are summarized in the silberberg figure (ifcomparo) Recall/review from chem 201 what dipoles and polar compounds are. Due to the overall geometry of the molecule (ax2e2; tetrahedral class) the water molecule is polar overall as well. Carbon dioxide on the other hand while containing polar c=o bonds, due to symmetry (ax2; linear) the dipoles cancel out and the molecule is consider non-polar. Many molecules contain dipoles, and dipole-dipole if is available to all polar molecules.
