2.2.2 - Shapes of molecules Flashcards

Linear

bond angle: 180^o

2 electron pairs: 2 bonding, 0 lone.

Trigonal planar

bond angle: 120^o

3 electron pairs: 3 bonding, 0 lone

non-linear (bent) (one lone pair)

bond angle 118^o

3 electron pairs: 2 bonding, 1 lone

Tetrahedral

bond angle: 109.5^o

4 electron pairs: 4 bonding, 0 lone

Trigonal Pyramidal

bond angle: 107^o

4 electron pairs: 3 bonding, 1 lone

Non linear (2 lone pairs)

bond angle: 104.5^o

4 electron pairs: 2 bonding, 2 lone

Trigonal bipyramidal

bond angle: 120^o, 90^o

5 electron pairs: 5 bonding, 0 lone

trigonal pyramidal or see saw

bond angle:119^o,89^o

5 electron pairs: 4 bonding, 1 lone

Trigonal planar or t shape

bond angle: 120^o, 89^o

5 electron pairs: 3 bonding, 2 lone

octahedral

bond angle: 90^o

6 electron pairs: 6 bonding, 0 lone

square pyramid

bond angle: 89^o

6 electron pairs: 5 bonding, 1 lone

square planar

bond angle: 90^o

6 electron pairs: 4 bonding, 2 lone

What is the VSEPR theory

a model used in chemistry for explaining and predicting the shapes of molecules and polyatomic ions:

No. of electron pairs determine the shape
Electron pairs repel each other to be as far apart as possible
Arrangement of electrons minimise repulsion, holding the the bonded atoms in a definitive shape