Common Textbook and Teaching Misrepresentations of Lewis Structures

Abstract

Current freshman chemistry textbooks commonly advise the drawing of Lewis structures with much emphasis on the reduction of formal charge and little on the preservation of the octet rule. This currently accepted method produces structures different from the original Lewis structures, which rarely had expanded valence shells on central atoms. Computational results from Gaussian 92 have shown us that the leading resonance structures cited in freshman chemistry textbooks are often not the most accurate to represent the molecules and are, at best, minor resonance structures, whose presentation is not worth the confusion that it causes for many first-year students. Instead, the Lewis structures that most accurately represent these molecules are the original Lewis structures, which generally abide by the octet rule. If the octet rule is more strongly stressed in the teaching of Lewis structures-thus avoiding the many complications and sources of confusion related to valence-shell expansion and reduction of form...