Covalent Bonding and Molecular Geometry The objective of this exercise is to help in understanding the geometric relationships of atoms in simple molecules and the relationship of hybridization to the geometry present. In the last 30 years, data obtained from spectrometric measurements, X?ray and electron diffraction studies, and other experiments have yielded precise information about bond distances, angles, and energies. In many cases, the data confirmed conclusions reached earlier. In other cases, valuable new insights were acquired. Structure theory has advanced far beyond the simple electron dot representations and now rests securely on the foundations of quantum and wave mechanics. Although problems involving only simple molecules can now be solved with mathematical rigor, approximations such as the valence bond theory and the molecular orbital theory are very successful in giving results that agree with experimental measurements.This exercise will use valence bond theory or hybridization to look at the geometry formed from various hybridizations. You will use a framework model kit which gives the correct angles for the each of these hybridizations.The first bond formed between any two atoms is always a sigma (s)?bond (one that is symmetric about the bond axis). Additional bonds between the same two atoms will be pi (p)?bonds (perpendicular to the bond axis). It is the sigma?bonds and any lone?pairs of electrons occupying the sigma hybrid orbitals that determine the geometry of a molecule. Pi?bonds are always perpendicular to the sigma?bonds and follow the geometry formed by the sigma?bonding.ProcedureCheck out a molecular model kit from the stockroom. Read the kit directions to see which framework center is used for each hybridization.Tetrahedral (sp3 hybridization)CH4Construct a model of methane using a tetrahedral center (4 prongs) and four rods of the same color to show how the 4 H's are attached.GeometryLewis dot diagram# o...
