Shapes of Molecules

What is the VSEPR theory?

What is the VSEPR theory?

It predicts the shapes of molecules based on the idea that electrons repel each other.

what is outlined in VSEPR

lone pair- lone pair= greatest repulsion lone pair- bonding pair= medium repulsion bonding pair- bonding pair= smallest repulsion

2 bonding pairs

linear, 180 degrees, all bonding pairs repelled equally

3 bonding pairs

trigonal planar, 120 degrees, all bp repelled equally

4 bonding pairs

tetrahedral, 109.5 degrees, all bp repelled equally

3 bonding pairs 1 lone pair

trigonal pyramidal, 107 degrees; lone pair and bp repel more than 2 bp's, so bp's are pushed closer together

2 bonding pairs 1 lone pair

Non-linear (bent), 117.5 degrees

2 bonding pairs 2 lone pairs

bent, 104.5 degrees; lp,lp repulsion> lp, bp repulsion> bp bp repulsion

5 bonding pairs

trigonal bipyramidal, 90 degrees and 120 degrees; all bp repelled equally

3 bonding pairs 2 lone pairs

trigonal planar, 120 degrees; the repulsion from the lone pairs on one side equalises the repulsion from the lone pair on the other side

6 bonding pairs

Octahedral, 90 degrees, 180 degrees; all bp repelled equally