CHEM101 Lecture Notes - Lecture 15: Pentagonal Bipyramid, Square Planar Molecular Geometry, Molecular Geometry

• School: University of Alberta
• Department: Chemistry
• Course: CHEM101
• Professor: Rylan Lundgren

Document Summary

Electron pairs in a molecule will arrange themselves so they are as far away from the other electrons in the molecule. Vespr: start with lewis structure, determine the number of points in spaces on the central atom. When drawing a vespr structure you have to draw the dimensions, unlike a lewis diagram. Two electron groups: two points in space, 180 degrees between them (linear molecule, ax2 element system) Exception: ax2 e where e is a lone e- pair resulting in a bent straight line. Three electron groups: three points in space, trigonal arrangement to keep e- away from each other, 120 degrees is the ideal bond angle. (trigonal or trigonal planar, Four electron groups: four points in space, tetrahedral shape, need to indicate that one part of the molecule is going into space and one is coming out of the page. Again there"s an exception when there is a lone e- pair.