1. Chem. 212 – Molecular Structures and Geometries Hand in to TA: VSEPR-Pre-lab; Solubility Report, GCF’s. Pick up one Model Kit per group. Hybridization of carbon Follow Sequence of:Lewis -> AXE -> VSEPR Follow format (see later slide) methane ethane vs. ethene vs. ethyne Lab report due next week: (Tue-Group next Tue 9:30 am); (Wed-Group next Wed 2:00 pm); (Fri-Group next Thu 12:00 nn). CyberChem (VSEPR) video

2. Hybridization of Carbon E 2s 2p Free CarbonBonding in Carbon Four Equivalent sp 3 Hybridized Orbitals (Tetrahedral)  Methane  Ethane versus Ethene (Geometrical Isomers)  Ethyne  Bromochloroiodomethane (Stereoisomers)

3. Drawing Lewis Structures Follow Step by Step Method (See Ng Web-site)Ng Web-site 1.Total all valence electrons. [Consider Charge] 2.Write symbols for the atoms and guess skeleton structure [ define a central atom ]. 3.Place a pair of electrons in each bond. 4.Complete octets of surrounding atoms. [ H = 2 only ] 5.Place leftover electrons in pairs on the central atom. 6.If there are not enough electrons to give the central atom an octet, look for multiple bonds by transferring electrons until each atom has eight electrons around it. HyperChem CyberChem video

4. Summary of VSEPR Molecular Shapes e-pairsNotation Name of VSEPR shape Examples 2AX 2 LinearHgCl 2, ZnI 2, CS 2, CO 2 3AX 3 Trigonal planarBF 3, GaI 3 AX 2 ENon-linear (Bent)SO 2, SnCl 2 4AX 4 TetrahedralCCl 4, CH 4, BF 4 - AX 3 E(Trigonal) PyramidalNH 3, OH 3 - AX 2 E 2 Non-Linear (Bent)H 2 O, SeCl 2 5AX 5 Trigonal bipyramidalPCl 5, PF 5 AX 4 EDistorted tetrahedral (see-sawed) TeCl 4, SF 4 AX 3 E 2 T-ShapedClF 3, BrF 3 AX 2 E 3 LinearI 3 -, ICl 2 - 6AX 6 OctahedralSF 6, PF 6 - AX 5 ESquare PyramidalIF 5, BrF 5 AX 4 E 2 Square PlanarICl 4 -, BrF 4 - See Ng Web-site HyperChemCyberChem video

5. Lewis/AXE/VSEPR Format Formula/Name (Total # valence e - ) Lewis Structure and AXE Notation VSEPR 3D Drawing Name of Shape of all possible central atoms PF 3 phosphorus trifluoride (26)