Harold H. Schobert'
Iowa State Un~versitv Ames,
Iowa 50010
II
A Magnetic Analogy for Demonstrating Some VPPR Principles
The valence-shell electron-pair repulsion theory (I) is a useful framework for providing students with a mechanism for predicting the geometry of small molecules. A discussion of the principles of VSEPR has been presented in a diverse array of general chemistry texts (2-6) and a t least one laboratory manual (7). The demonstrations described here were done as part of a videotape introduction to a lahoratory exercise on VSEPR (71, but it is felt that they could be if use in other situations as well. The central issue of the discussion was a comparison of the electron density of a honding pair of elec