+ bonding part iii unit 5: bonding mrs. callender vs e p r
TRANSCRIPT
+
Bonding Part III
Unit 5: BondingMrs. Callender
V S
E P
R
+Lesson Essential Question:
How do I Predict Molecular Shape?
+VSEPR stands for….
ValenceShell
ElectronPairRepulsion
The structure around a given atom is determined principally by minimizing electron pair repulsions.
+How to predict a VSEPR Structure?
1. Draw a Lewis Dot Structure
2. Put pairs as far apart as possible.
3. Determine position of atoms from the way the electron pairs are shared and unshared.
4. Determine the name of the molecular structure from positions of the atoms and electron pairs.
+Electron Pair Count and Geometry
Linear – two pairs on the central atom.
Trigonal – three pairs on the central atom.
Tetrahedral – four pairs on the central atom.
+How do I figure out the geometry?
Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
2 Linear,180o
2 BP Linear
BeCl2
Be– 2 valence e-2 Cl – 14 valence e-Total = 16 valence e- C
lBe
Cl
Two Bonding Pair (BP) of electrons and no unbonded pair of electrons fits the Linear criteria.
AB2E0
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
3Trigonal Planar,120o
3 BP Trigonal Planar
BF3
B– 3 valence e-3 F – 21 valence e-Total = 24 valence e- F B F
FThree Bonding Pair (BP) of electrons and no unbonded pair of electrons fits the Trigonal Planar criteria.
AB3E0
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
3Trigonal Planar,120o
2 BP1 LP
BentSO2
S – 6 valence e-2 O– 12 valence e-Total = 18 valence e-
O S OThis structure has resonance so the bonds between the S and O represent 2 Bonding Pairs (BP) of electrons.
One Lone Pair (LP) of electrons.
AB2E1
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
4 Tetrahedral109.5o
4 BPTetrahedra
l CH4
C – 4 valence e-4 H– 4 valence e-Total = 8 valence e-
H CH
HH
4 Bonding Pairs of electrons and no Lone Pair of electrons has this compound as a Tetrahedral.
AB4E0
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
4 Tetrahedral109.5o
3 BP1 LP
Trigonal Pyramidal
NH3
N – 5 valence e-3 H– 3 valence e-Total = 8 valence e-
H N HH
3 Bonding Pairs of electrons and one Lone Pair of electrons has this compound as a Trigonal Pyramidal.
AX3E1
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
4 Tetrahedral109.5o
2 BP2 LP
BentH2O
2 H – 2 valence e-O– 6 valence e-Total = 8 valence e- H O H
3 Bonding Pairs of electrons and Two Lone Pair of electrons has this compound as a Trigonal Pyramidal.
AB2E2
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
5 Trigonal Bipyramida
l120o, 90o
5 BP
Trigonal Bipyramidal
PCl5
P – 5 valence e- 5 Cl – 35 valence e-Total = 40 valence e-
Cl
PCl
Cl
ClCl
v
5 Bonding Pairs of electrons and no Lone Pair of electrons has this compound as a Trigonal Bipyramidal
Some elements can have EXPANDED Octets which means they can have more than the eight electrons around the central atom.
AX5E0
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
5 Trigonal Bipyramida
l120o, 90o
4 BP1 LP
See-Saw
SF4
S – 6 valence e-4 F – 28 valence e-Total = 34 valence e-
F SF
FF
v
4 Bonding Pairs of electrons and One Lone Pair of electrons has this compound as a See Saw
Some elements can have EXPANDED Octets which means they can have more than the eight electrons around the central atom.
AX4E1
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
5 Trigonal Bipyramida
l120o, 90o
3 BP2 LP
T-Shaped
ICl3
I – 7 valence e-3 Cl – 21 valence e-Total = 28 valence e-
Cl
ICl
Cl
3 Bonding Pairs of electrons and Two Lone Pair of electrons has this compound as T-Shaped.
Some elements can have EXPANDED Octets which means they can have more than the eight electrons around the central atom.
AX3E2
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
5 Trigonal Bipyramida
l120o, 90o
2 BP3 LP
Linear
I3-1
3 I – 21 valence e--1 charge – 1 valence e-Total = 22 valence e-
I I I 2 Bonding Pairs of electrons and Three Lone Pair of electrons has this compound as Linear.
Some elements can have EXPANDED Octets which means they can have more than the eight electrons around the central atom.
AX2E3
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
6 Octahedral90o
6 BP
Octahedral SF6
S – 6 valence e-6 F – 42 valence e-Total = 48 valence e-
Some elements can have EXPANDED Octets which means they can have more than the eight electrons around the central atom.
F S F F F
F F 6 Bonding Pairs of electrons and no Lone Pair of electrons has this compound as an Octahedral.
AX6E0
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
6 Octahedral90o
5 BP1 LP
Square Pyramid
IF5
I – 7 valence e-5 F – 35 valence e-Total = 42 valence e-
Some elements can have EXPANDED Octets which means they can have more than the eight electrons around the central atom.
F I F F F
F 5 Bonding Pairs of electrons and One Lone Pair of electrons has this compound as a Square Pyramidal.
AX5E1
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
6 Octahedral90o
4 BP2 LP
Square Planar
XeF4
Xe – 8 valence e-4 F – 28 valence e-Total = 32 valence e-
Some elements can have EXPANDED Octets which means they can have more than the eight electrons around the central atom.
FXe
F
F F
4 Bonding Pairs of electrons and Two Lone Pair of electrons has this compound as a Square Planar
AX4E2
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
7 Pentagonal Bipyramid
7 BP
Pentagonal Bipyramid
IF7
I – 7 valence e-7 F – 49 valence e-Total = 56 valence e-
Some elements can have EXPANDED Octets which means they can have more than the eight electrons around the central atom.
AX7E0
FIF
F F
F F F
7 Bonding Pairs of electrons and No Lone Pair electrons has this compound as a Pentagonal Bipyramid.
+Electron Pair #
GeometricalArrangement
Types of e- Pairs
Molecular Shapes
Ex’s Ball and Stick Model
7 Pentagonal Bipyramid
6 BP1 LP
Pentagonal Pyramidal
IOF5-2
I – 7 valence e-5 F – 35 valence e-O – 6 valence e--2 charge – 2 valence e-Total = 50 valence e-Some elements
can have EXPANDED Octets which means they can have more than the eight electrons around the central atom.
AX6E1
IO
F F
F F F
6 Bonding Pairs of electrons and One Lone Pair electrons has this compound as a Pentagonal Pyramidal.
+Dotted Line and Wedge Model
Linear AX2E0
Trigonal Planar AX3E0
Bent AX2E1
+Dotted Line and Wedge Model
Tetrahedral AX4E0
Trigonal Pyramidal AX3E1
Bent AX2E2
+Dotted Line and Wedge Model
Octahedral AX6E0
Square Pyramid AX5E1
Square Planar AX4E2
+Dotted Line and Wedge Model
Pentagonal Bipyramid AX7E0
Pentagonal Pyramid AX6E1