Exam #4 Review Session Chem 111, Fall 2009

Bond Properties Length Order Strength Polarity

Periodic Table

Bond Properties Which atom is more electronegative?  B or C  N or P Which bond is most polar?  C-C or C-O or C-F  C-O or C-S Which bond is the longest?  C-O or C-F  C-O or C=O

Lewis Structures Why We Love Them (and you know we do!) Drawing a Lewis Structure: – Calculating formal charge – Determining which resonance structure is best Use Lewis Structure to: – Determine bond order – Determine electron pair and molecular geometry – Calculate formal charge and oxidation numbers – Determine hybridization and bond types

Draw a Lewis Structure for CS 2

Periodic Table

Formal Charges and Oxidation Numbers : : : : : :

Molecular Geometry # Structural Pairs Electron Pair Geometry Angle Molecular Geometry Number of Lone Pairs Linear180°Linear 3trigonal planar120°trigonal planarbent 4tetrahedral109.5°tetrahedral trigonal pyramidal bent 5 trigonal bipyramidal 90° 120° 180° trigonal bipyramidal see-sawT-shapedLinear 6octahedral 90° 180° octahedral square pyramidal square planar

Molecular Geometry for Propane, 1-Propanol, and Propene : :

Hybridization and Bond Types for Propane, 1- Propanol, and Propene : :

Hybrid Orbital Geometry