CH 301 Ch13 VSEPR examples 1 answers v2 - Boron Trichloride...

Boron Trichloride, BCl
3
Valence e = 3 + (3x7) = 24
B
Cl Cl
Cl
RHED = 3 TRIGONAL PLANAR
POLAR covalent bonds;
NON POLAR molecule
120°
1
2
0
°
RHED = 3
TRIGONAL PLANAR
No
TRIGONAL PLANAR
Electronic geometry =
lone pairs on B
Molecular geometry =
NON POLAR
POLAR
molecule
120 °

Methane
,
CH
4
Valence e = 4 + (4x1) = 8
C
H H
H
H
RHED =
Very slightly POLAR covalent bonds;
NON POLAR molecule
C
H
H
H
H
REDRAW!!
ALL
ANGLES
4
TETRAHEDRAL
No
TETRAHEDRAL
Electronic geometry =
lone pairs on C
Molecular geometry =
NON POLAR
Slightly POLAR
molecule
109.5 °

Ammonia
,
NH
3
Valence e = 5 + (3x1) = 8
POLAR covalent bonds;
due to lone pair,
POLAR molecule
N
H H
H
N
H
H
H
REDRAW!!
lone pair needs more room:
ALL HNH ANGLES 09.5 °
RHED = 4
TETRAHEDRAL
TRIGONAL PYRAMIDAL
Electronic geometry =
Molecular geometry =
POLAR
POLAR
molecule
<109.5 °
One
lone pair on N
Due to lone pair,

Freon 12
,
CCl
2
F
2
Valence e = 4 + (4x7) = 32
POLAR covalent bonds;
dipoles do not cancel:
POLAR molecule
C
Cl
Cl
F
F
REDRAW!!
C
Cl
F
F
Cl
POLAR
POLAR
molecule
dipoles do not cancel:
4 RHED:
tetrahedral
electronic and
molecular
geometry
all 109.5 °

A series of related molecules – which are polar?