CHEM 1201 Chapter : Chem Ch 9
Document Summary
Ccl4: experimentally we find all cl c cl bond angles are 109. 5 . The molecule cannot be planar: all cl atoms are located at the vertices of a tetrahedron with the c at its center. What determines the shape of a molecule: we assume that the valence electrons repel each other, to minimizes this repulsion, the molecule adopts the 3d geometry. The vsepr model: the valence-shell electron-pair repulsion (vsepr) model, we can refer to the electron pairs as electron domains, bonding pair of e- (covalent bond, nonbonding pair (lone pair) Multiple bonds are counted as one electron domain. The central atom a has 4 electron domains. The vsepr model: we use the electron domain geometry to help us predict the molecular geometry. To determine the electron domain geometry: draw the lewis structure, count the total number of e- domains around the central atom, arrange the electron domains in one of the above geometries to minimize electron-electron repulsion.
