exam #4 review session chem 111, fall 2009. bond properties length order strength polarity
TRANSCRIPT
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 StructuresWhy 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
Molecular Geometry
# Structural Pairs
Electron Pair Geometry Angle
Molecular Geometry
Number of Lone Pairs
0 1 2 3
4 Linear 180° Linear
3 trigonal planar 120° trigonal planar bent bent
4 tetrahedral 109.5° tetrahedral trigonal pyramidal bent
5 trigonal bipyramidal
90° 120°180°
trigonal bipyramidal see-saw T-shaped Linear
6 octahedral 90°180° octahedral square
pyramidalsquare planar