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http://lawrencekok.blogspot.com
Prepared by
Lawrence Kok
Tutorial on VSEPR.
brown liquid
yellow gas
greenish gas
violet solid
Covalent bonding between non metals
Gp 17 Non metalGp 17 Non metal
Non m...
brown liquid
yellow gas
greenish gas
violet solid
Covalent bonding between non metals
2.8.7
Gp 17 Non metal
achieve stable...
brown liquid
Click here simulation on covalent bond
yellow gas
greenish gas
violet solid
Covalent bonding between non meta...
Bond length and Bond strength
Bond length = 0.199nm
Lewis structure/diagram
. Electron cross dot
. Valence/bonding pair el...
Bond Bond
order
Bond
strength
Bond
length/pm
C - C 1 347 154
C = C 2 612 134
C Ξ C 3 820 120
N - N 1 159 145
N = N 2 418 1...
Bond Bond
order
Bond
strength
Bond
length/pm
C - C 1 347 154
C = C 2 612 134
C Ξ C 3 820 120
N - N 1 159 145
N = N 2 418 1...
:
.
CI
..
x
Bond Bond
order
Bond
strength
Bond
length/pm
C - C 1 347 154
C = C 2 612 134
C Ξ C 3 820 120
N - N 1 159 145
N...
Valence Shell Electron Pair Repulsion
Predict molecular shape/geometry Shape determine by electron pairs/
electron charge ...
Valence Shell Electron Pair Repulsion
Predict molecular shape/geometry Shape determine by electron pairs/
electron charge ...
Valence Shell Electron Pair Repulsion
Predict molecular shape/geometry Shape determine by electron pairs/
electron charge ...
Valence Shell Electron Pair Repulsion
Principles of VSEPR
Determine number valence e around central atom1
..
N
HHH
3 bondi...
Valence Shell Electron Pair Repulsion
Principles of VSEPR
Determine number valence e around central atom1
2 Single, double...
Valence Shell Electron Pair Repulsion
Principles of VSEPR
Determine number valence e around central atom1
2 Single, double...
Valence Shell Electron Pair Repulsion
Bonding/lone pair arrange themselves as far as possible
(minimise repulsion)
Princip...
Valence Shell Electron Pair Repulsion
Bonding/lone pair arrange themselves as far as possible
(minimise repulsion)
Princip...
H
Linear
Bond angle - 180°
O
OO C BeH N
 X
 x
O C H NO
C OO CH N HH Be N OX
x
 X
X 
X 
X 
X
X
 X
 x
X
x
+
+
...
H
Linear
Bond angle - 180°
O
OO C BeH N
B
 X
 x
C SO
O C H NO
C OO CH N HH Be N OX
x
 X
X 
X 
X 
X
X
 X
 x
X
...
H
Bond angle - 104.5°
Linear
Bond angle - 180°
O
OO C BeH N
B
 X
 x
C SO
O C H NO
C OO CH N HH Be N OX
x
 X
X 
X 
X...
Bond angle -104.5°
:
O
HH
H2O
H H
O
O
F2O
F F
F F
O
S
CICI
SCI2
N
H H
S
CI CI
N
H
NH2
-
-
-
H: : : : :
:
:
:
:
: : Bent
Lo...
Bond angle -104.5°
O
Bond angle- 107°
Trigonal
Pyrimidal
N
H
N
:
:
O
SO3
2-PH3NH3
O
HH
H2O
H H
O
O
F2O
F F
F F
O
S
CICI
SC...
Bond angle -109.5°
Bond angle -104.5°
O
Bond angle- 107°
Tetrahedral
Trigonal
Pyrimidal
N
H
N
:
:
O
SO3
2-PH3NH3
O
HH
H2O
...
Trigonal
Bipyrimidal
Bond angle - 90° , 120°
P CI
CI
CI
CI
CI
P

CI
 CI
CI
CI

CI
PCI5Bonding
Pair
Lone
Pair
E
L
E
C...
Bond angle <90° , <120°
Trigonal
Bipyrimidal
Bond angle - 90° , 120°
P CI
CI
CI
CI
CI
:
P

CI
 CI
CI
CI

S
F
F
F
F
S...
Bond angle <90°
T shape
Bond angle <90° , <120°
Trigonal
Bipyrimidal
Bond angle - 90° , 120°
P CI
CI
CI
CI
CI
:
P

CI
...
:
:
:
:
:
:
Linear
Bond angle 180°
Bond angle <90°
T shape
Bond angle <90° , <120°
Trigonal
Bipyrimidal
Bond angle - 90° ,...
F
S
SF6
F
F
F
F
F
PCI6
-
P
CI
CI
CI
CI
CI
CI
IF5O
I
O
||
F
F
F
F
F
F

S
F

F
F
F
F
CI
P
CI


CI
CI
CI
CI
I
F
F
F
...
F
S
SF6
F
F
F
F
F
PCI6
-
P
CI
CI
CI
CI
CI
CI
IF5O
I
O
||
F
F
F
F
F
F

S
F

F
F
F
F
CI
P
CI


CI
CI
CI
CI
I
F
F
F
...
Square
planar
F
S
SF6
F
F
F
F
F
PCI6
-
P
CI
CI
CI
CI
CI
CI
IF5O
I
O
||
F
F
F
F
F
F

S
F

F
F
F
F
CI
P
CI


CI
CI
C...
Square
planar
F
S
SF6
F
F
F
F
F
PCI6
-
P
CI
CI
CI
CI
CI
CI
IF5O
I
O
||
F
F
F
F
F
F

S
F

F
F
F
F
CI
P
CI


CI
CI
C...
Linear
Square
planar
F
S
SF6
F
F
F
F
F
PCI6
-
P
CI
CI
CI
CI
CI
CI
IF5O
I
O
||
F
F
F
F
F
F

S
F

F
F
F
F
CI
P
CI


...
H
O
OO C BeH N
B
 X
 x
C SO
O C H NO
C OO CH N HH Be N OX
x
 X
X 
X 
X 
X
X
 X
 x
X
x
+
+
:
F
F
F
H
H O O
O
...
H
Bond angle
104.5°
Bond angle
180°
O
OO C BeH N
B
 X
 x
C SO
O C H NO
C OO CH N HH Be N OX
x
 X
X 
X 
X 
X
X
 ...
H
Bond angle
104.5°
Linear
Bond angle
180°
O
OO C BeH N
B
 X
 x
C SO
O C H NO
C OO CH N HH Be N OX
x
 X
X 
X 
X 
...
O
N
H
N
:
:
O
SO3
2-PH3NH3
O
HH
H2O
H H
O
O
F2O
F F
F F
O
S
CICI
SCI2
N
H H
S
CI CI
N
H
NH2
-
-
-
H: : : : :
:
:
:
:
: :
C...
Bond angle
109.5°
Bond angle
104.5°
O
Bond angle
107°
N
H
N
:
:
O
SO3
2-PH3NH3
O
HH
H2O
H H
O
O
F2O
F F
F F
O
S
CICI
SCI2
...
Bond angle
109.5°
Bond angle
104.5°
O
Bond angle
107°
Tetrahedral
Trigonal
Pyrimidal
N
H
N
:
:
O
SO3
2-PH3NH3
O
HH
H2O
H H...
P CICI
CI
CI
CI
:
P

CI
 CI
CI
CI


S
F
F
F
F
S
F


F
F
F
Te
CI
CI
CI
CI
Te
CI
CI
CI
CI
:
CI
F
F
F
CI
F
...
Bond angle
180°
Bond angle
<90°
Bond angle
< 90° , < 120°
Bond angle
90° , 120°
P CICI
CI
CI
CI
:
P

CI
 CI
CI
CI

...
Bond angle
180° Linear
Bond angle
<90°
T shape
Bond angle
< 90° , < 120°
Trigonal
BipyrimidalBond angle
90° , 120°
P CICI
...
F
S
SF6
F
F
F
F
F
PCI6
-
P
CI
CI
CI
CI
CI
CI
IF5O
I
O
||
F
F
F
F
F
F

S
F

F
F
F
F
CI
P
CI


CI
CI
CI
CI
I
F
F
F
...
F
S
SF6
F
F
F
F
F
PCI6
-
P
CI
CI
CI
CI
CI
CI
IF5O
I
O
||
F
F
F
F
F
F

S
F

F
F
F
F
CI
P
CI


CI
CI
CI
CI
I
F
F
F
...
Linear
Square planar
F
S
SF6
F
F
F
F
F
PCI6
-
P
CI
CI
CI
CI
CI
CI
IF5O
I
O
||
F
F
F
F
F
F

S
F

F
F
F
F
CI
P
CI


...
Valence Shell Electron Pair Repulsion
Predict molecular shape/geometry Shape determine by electron pairs/
electron charge ...
Acknowledgements
Thanks to source of pictures and video used in this presentation
Thanks to Creative Commons for excellent...
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IB Chemistry on VSEPR

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IB Chemistry on VSEPR

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Transcript of "IB Chemistry on VSEPR"

  1. 1. http://lawrencekok.blogspot.com Prepared by Lawrence Kok Tutorial on VSEPR.
  2. 2. brown liquid yellow gas greenish gas violet solid Covalent bonding between non metals Gp 17 Non metalGp 17 Non metal Non metal • High EN value • Gain electron (anion) • Electronegative ions Covalent Bond Group 17 Non metal • High EN value • Gain electron (anion) • Electronegative ions
  3. 3. brown liquid yellow gas greenish gas violet solid Covalent bonding between non metals 2.8.7 Gp 17 Non metal achieve stable octet structure CI 2.8.8 2.8.7 Sharing electron Gp 17 Non metal 2.8.8 CI Non metal • High EN value • Gain electron (anion) • Electronegative ions Covalent Bond Group 17 Non metal • High EN value • Gain electron (anion) • Electronegative ions
  4. 4. brown liquid Click here simulation on covalent bond yellow gas greenish gas violet solid Covalent bonding between non metals 2.8.7 Gp 17 Non metal achieve stable octet structure CI shared pair electron Covalent Bonding Electrostatic forces attraction between nucleus with shared pair electron 2.8.8 2.8.7 Sharing electron Gp 17 Non metal 2.8.8 CI Non metal • High EN value • Gain electron (anion) • Electronegative ions Covalent Bond Group 17 CICI Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron CI CI: x x :: :. x x X x x x x CI CI :: x x x x CI CI Non metal • High EN value • Gain electron (anion) • Electronegative ions Single covalent bond – shared pair electron
  5. 5. Bond length and Bond strength Bond length = 0.199nm Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron CI CI: x x :: : : . x x X X x x x x O CI CI:: x x x x x x CI CI O O: x x O N O O N: Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron : : . N N: N N Bond length = 0.121nm Bond length = 0.110nm
  6. 6. Bond Bond order Bond strength Bond length/pm C - C 1 347 154 C = C 2 612 134 C Ξ C 3 820 120 N - N 1 159 145 N = N 2 418 123 N Ξ N 3 914 110 Bond length and Bond strength Bond length = 0.199nm Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron CI CI: x x :: : : . x x X X x x x x O CI CI:: x x x x x x CI CI O O: x x O N O O N: Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron : : . N N: N N Triple bond > Double bond > Single bond Bond length decrease Bond strength Increase (Double/Triple bond) Bond length = 0.121nm Bond length = 0.110nm Bond order up – Bond strength up – Bond length down
  7. 7. Bond Bond order Bond strength Bond length/pm C - C 1 347 154 C = C 2 612 134 C Ξ C 3 820 120 N - N 1 159 145 N = N 2 418 123 N Ξ N 3 914 110 Bond length and Bond strength Bond length = 0.199nm Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron CI CI: x x :: : : . x x X X x x x x O CI CI:: x x x x x x CI CI O O: x x O N O O N: Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron O : : . N N: N N : Triple bond > Double bond > Single bond Bonding pair e -involve in bonding Bond length decrease Bond strength Increase (Double/Triple bond) Bond length = 0.121nm Bond length = 0.110nm Bond order up – Bond strength up – Bond length down O: Non bonding pair (Lone pair electron) Bonding pair electron C O: : Bonding pair electron Dative bond (electron pair of oxy) Types of bonding Lone pair e –not involve in bonding Dative/coordinate bond - pair e come from an atom
  8. 8. : . CI .. x Bond Bond order Bond strength Bond length/pm C - C 1 347 154 C = C 2 612 134 C Ξ C 3 820 120 N - N 1 159 145 N = N 2 418 123 N Ξ N 3 914 110 Bond length and Bond strength Bond length = 0.199nm Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron CI CI: x x :: : : . x x X X x x x x O CI CI:: x x x x x x CI CI O O: x x O N O O N: Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron Lewis structure/diagram . Electron cross dot . Valence/bonding pair electron O : : . N N: N N : Triple bond > Double bond > Single bond Bonding pair e -involve in bonding Bond length decrease Bond strength Increase (Double/Triple bond) Bond length = 0.121nm Bond length = 0.110nm Bond order up – Bond strength up – Bond length down O: Non bonding pair (Lone pair electron) Bonding pair electron C O: : Bonding pair electron Dative bond (electron pair of oxy) Types of bonding Lone pair e –not involve in bonding Dative/coordinate bond - pair e come from an atom Exception to octet rule All period 2 element - observe octet rule except Be and B Electron deficient Less than 8 valence e Expanded octet More than 8 valence e All period 3 element - observe octet rule except P and S : BeCI CIx . : :: :: x x. Be - 4 valence e BCI CI : :: : :: x : :B - 6 valence e P S CI CI CI CI CI CI CICI CICI CI P - 10 valence e S – 12 valence e
  9. 9. Valence Shell Electron Pair Repulsion Predict molecular shape/geometry Shape determine by electron pairs/ electron charge centers/ECC Valence Shell Electron Pair Repulsion NOT surrounding atoms N H HH .. Shape of molecule Lewis structure VSEPR .. N H H H Shape
  10. 10. Valence Shell Electron Pair Repulsion Predict molecular shape/geometry Shape determine by electron pairs/ electron charge centers/ECC Bonding/lone pair – repel each other Bonding/lone pair arrange themselves as far as possible (minimise repulsion) Valence Shell Electron Pair Repulsion NOT surrounding atoms N H HH .. Principles of VSEPR Shape of molecule Determine number valence e around central atom1 2 Single, double, triple bond , lone pair act as electron charge center/ECC 3 4 Lone pair-lone pair > Lone pair-bonding pair > bonding pair-bonding pair repulsion 5 6 ECC or electron pair position in equatorial first, then axial Lewis structure VSEPR .. N H H H Shape
  11. 11. Valence Shell Electron Pair Repulsion Predict molecular shape/geometry Shape determine by electron pairs/ electron charge centers/ECC Bonding/lone pair – repel each other Bonding/lone pair arrange themselves as far as possible (minimise repulsion) Valence Shell Electron Pair Repulsion NOT surrounding atoms N H HH .. Principles of VSEPR Shape of molecule Determine number valence e around central atom1 2 Single, double, triple bond , lone pair act as electron charge center/ECC 3 4 Lone pair-lone pair > Lone pair-bonding pair > bonding pair-bonding pair repulsion 5 6 ECC or electron pair position in equatorial first, then axial Excellent VSEPR simulation Click here ✓ Click here VSEPR notes Lewis structure VSEPR .. N H H H Shape Click here VSEPR simulation
  12. 12. Valence Shell Electron Pair Repulsion Principles of VSEPR Determine number valence e around central atom1 .. N HHH 3 bonding pair 1 lone pair 4 ECC N – central atom
  13. 13. Valence Shell Electron Pair Repulsion Principles of VSEPR Determine number valence e around central atom1 2 Single, double, triple bond , lone pair act as electron charge center/ECC .. N HHH 3 bonding pair 1 lone pair 4 ECC N – central atom 3 ECC C H =O H H C N 2 ECC OH H 4 ECC
  14. 14. Valence Shell Electron Pair Repulsion Principles of VSEPR Determine number valence e around central atom1 2 Single, double, triple bond , lone pair act as electron charge center/ECC 3 Bonding/lone pair repel each other Lone /lone pair > Lone /bond pair > bond/bond pair repulsion .. N HHH 3 bonding pair 1 lone pair 4 ECC N – central atom 3 ECC C H =O H H C N 2 ECC OH H 4 ECC > > 1 lone pair2 lone pair 0 lone pair Repulsion greater - Bond angle smaller Repulsion greater Repulsion greater ✓
  15. 15. Valence Shell Electron Pair Repulsion Bonding/lone pair arrange themselves as far as possible (minimise repulsion) Principles of VSEPR Determine number valence e around central atom1 2 Single, double, triple bond , lone pair act as electron charge center/ECC 3 Bonding/lone pair repel each other Lone /lone pair > Lone /bond pair > bond/bond pair repulsion 4 5 .. N HHH 3 bonding pair 1 lone pair 4 ECC N – central atom 3 ECC C H =O H H C N 2 ECC OH H 4 ECC > > 1 lone pair2 lone pair 0 lone pair Repulsion greater - Bond angle smaller Repulsion greater Repulsion greater ✓ ECC far apart – Bond angle greatest – minimise repulsion Lone pair need more space Multiple bonds more space Unequal repulsionEqual repulsion 109.5° 107°
  16. 16. Valence Shell Electron Pair Repulsion Bonding/lone pair arrange themselves as far as possible (minimise repulsion) Principles of VSEPR Determine number valence e around central atom1 2 Single, double, triple bond , lone pair act as electron charge center/ECC 3 Bonding/lone pair repel each other Lone /lone pair > Lone /bond pair > bond/bond pair repulsion 4 5 For 5/6 ECC: ECC position in equatorial first, then axial .. N HHH 3 bonding pair 1 lone pair 4 ECC N – central atom 3 ECC C H =O H H C N 2 ECC OH H 4 ECC > > 1 lone pair2 lone pair 0 lone pair Repulsion greater - Bond angle smaller Repulsion greater Repulsion greater ✓ ECC far apart – Bond angle greatest – minimise repulsion 6 Lone pair need more space Multiple bonds more space Unequal repulsionEqual repulsion 90° 120° 109.5° 107° 180°
  17. 17. H Linear Bond angle - 180° O OO C BeH N  X  x O C H NO C OO CH N HH Be N OX x  X X  X  X  X X  X  x X x + + : CO2 HCN BeH2 NO2 +Lone Pair Bonding Pair Geometry 2 bond pair ✓ E L E C T R O N C E N T E R
  18. 18. H Linear Bond angle - 180° O OO C BeH N B  X  x C SO O C H NO C OO CH N HH Be N OX x  X X  X  X  X X  X  x X x + + : F F F H H O O O C O O O B X F F F C H H x x O S O O C O x x O 2- 2- O x x : || BF3 CH2 O SO3 CO3 2- CO2 HCN BeH2 NO2 +Lone Pair Bonding Pair Geometry 2 bond pair ✓ = = Geometry 3 bond pair Bond angle - 120° Trigonal planar ✓ E L E C T R O N C H A R G E C E N T E R E L E C T R O N C E N T E R
  19. 19. H Bond angle - 104.5° Linear Bond angle - 180° O OO C BeH N B  X  x C SO O C H NO C OO CH N HH Be N OX x  X X  X  X  X X  X  x X x + + : F F F H H O O O C O O O B X F F F C H H x x O S O O C O x x O 2- 2- O x x : || BF3 CH2 O SO3 CO3 2- CO2 HCN BeH2 NO2 +Lone Pair Bonding Pair Geometry 2 bond pair ✓ = = Geometry 3 bond pair Bond angle - 120° Trigonal planar ✓ E L E C T R O N C H A R G E C E N T E R O3 O O O : O O : O NO2  N OO  N OO NO2 - N OO : N OO : SO2 OO - - S : S OO : Geometry 2 bond pair 1 lone pair Bent ✓ E L E C T R O N C E N T E R
  20. 20. Bond angle -104.5° : O HH H2O H H O O F2O F F F F O S CICI SCI2 N H H S CI CI N H NH2 - - - H: : : : : : : : : : : Bent Lone Pair Bonding Pair E L E C T R O N C H A R G E C E N T E R Geometry 2 bond pair 2 lone pair ✓
  21. 21. Bond angle -104.5° O Bond angle- 107° Trigonal Pyrimidal N H N : : O SO3 2-PH3NH3 O HH H2O H H O O F2O F F F F O S CICI SCI2 N H H S CI CI N H NH2 - - - H: : : : : : : : : : : Bent CIO3 - H H P H H H H H H P H H H : O O S O S O : O 2- 2- CI O O O CI : O O - : : : : : Lone Pair Bonding Pair E L E C T R O N C H A R G E C E N T E R Geometry 2 bond pair 2 lone pair Geometry 3 bond pair 1 lone pair ✓ ✓ -
  22. 22. Bond angle -109.5° Bond angle -104.5° O Bond angle- 107° Tetrahedral Trigonal Pyrimidal N H N : : O SO3 2-PH3NH3 O HH H2O H H O O F2O F F F F O S CICI SCI2 N H H S CI CI N H NH2 - - - H: : : : : : : : : : : Bent CIO3 - H H P H H H H H H P H H H : O O S O S O : O 2- 2- CI O O O CI : O O - : CH4 C H NH4 + BH4 - PCI4 + H H H H C H H H  N H H H H H N H H H  H B HH H H B H  H H CI CI CI CI P CI CI CI P  CI - - + + + + :: : :: :: : : :: : : : : : Lone Pair Bonding Pair E L E C T R O N C H A R G E C E N T E R Geometry 2 bond pair 2 lone pair Geometry 3 bond pair 1 lone pair ✓ Geometry 4 bond pair ✓ - ✓
  23. 23. Trigonal Bipyrimidal Bond angle - 90° , 120° P CI CI CI CI CI P  CI  CI CI CI  CI PCI5Bonding Pair Lone Pair E L E C T R O N C H A R G E C E N T E R Geometry 5 bond pair ✓
  24. 24. Bond angle <90° , <120° Trigonal Bipyrimidal Bond angle - 90° , 120° P CI CI CI CI CI : P  CI  CI CI CI  S F F F F S F   F F F Te CI CI CI CI Te CI CI CI CI : I F F F F F I  F F  F Xe F F O O Xe  F  F O O : + + : CI ::::::: : : :: :: :: : : : : : :: : : :: : : : : : :: :: : :::: : : PCI5 SF4 TeCI4 (IF4)+ XeO2F2 Bonding Pair Lone Pair E L E C T R O N C H A R G E C E N T E R : : : : Geometry 5 bond pair ✓ Geometry 4 bond pair 1 lone pair Seesaw ✓
  25. 25. Bond angle <90° T shape Bond angle <90° , <120° Trigonal Bipyrimidal Bond angle - 90° , 120° P CI CI CI CI CI : P  CI  CI CI CI   S F F F F S F   F F F Te CI CI CI CI Te CI CI CI CI : CI F F F CI F  F F  I CI CI CI CI I   CI  CI I F F F F F I  F F  F Xe F F O O Xe  F  F O O : + + : CI ::::::: : : :: :: :: : : : : : :: : : :: : : : : : :: :: : :::: : : :: : :: : :: :: : :: : :: : : BrF F F Br F    F F : : : : : : :: : PCI5 SF4 TeCI4 (IF4)+ XeO2F2 CIF3 ICI3 BrF3 Bonding Pair Lone Pair E L E C T R O N C H A R G E C E N T E R : : : : Geometry 5 bond pair ✓ Geometry 4 bond pair 1 lone pair Seesaw ✓ Geometry 3 bond pair 2 lone pair ✓ (XeF3 )+ F F Xe F F Xe  F F :: : :: :: :: + +
  26. 26. : : : : : : Linear Bond angle 180° Bond angle <90° T shape Bond angle <90° , <120° Trigonal Bipyrimidal Bond angle - 90° , 120° P CI CI CI CI CI : P  CI  CI CI CI   S F F F F S F   F F F Te CI CI CI CI Te CI CI CI CI : CI F F F CI F  F F  I CI CI CI CI I   CI  CI I F F F F F I  F F  F Xe F F O O Xe  F  F O O : + + : CI I I I Xe CI CI I F F ::::::: : : :: :: :: : : : : : :: : : :: : : : : : :: :: : :::: : : :: : :: : :: :: : :: : :: : :: : :: :: :: :: :: :: : BrF F F Br F    F F : : : : : : :: : - PCI5 SF4 TeCI4 (IF4)+ XeO2F2 CIF3 ICI3 BrF3 (I3)- (ICI2)- XeF2 - Bonding Pair Lone Pair E L E C T R O N C H A R G E C E N T E R : : : : Geometry 5 bond pair ✓ Geometry 4 bond pair 1 lone pair Seesaw ✓ Geometry 3 bond pair 2 lone pair ✓ 2 bond pair 3 lone pair (XeF3 )+ F F Xe F F Xe  F F :: : :: :: :: + + ✓ Geometry
  27. 27. F S SF6 F F F F F PCI6 - P CI CI CI CI CI CI IF5O I O || F F F F F F  S F  F F F F CI P CI   CI CI CI CI I F F F  F F :: O : : :: : : : :: ::: : :: : :::: :: :: : : : :: : : : : :: : ::: : : : : :: : :: : :::: - - Lone Pair Bonding Pair E L E C T R O N C H A R G E C E N T E R Geometry 6 bond pair Bond angle - 90° Octahedral ✓
  28. 28. F S SF6 F F F F F PCI6 - P CI CI CI CI CI CI IF5O I O || F F F F F F  S F  F F F F CI P CI   CI CI CI CI I F F F  F F :: O Square pyrimidal  CI Sb Sb CI CI CICI CI CI CICI CI (SbCI5)2- BrF5 F Br F FF F F Br  F F O F F Xe || F FF F O :: Xe F F F F F Te F FF F F  Te F F F F XeOF4 (TeF5)- - - : : : : : : :: : : : :: ::: : :: : :::: :: : : : : : : : :: : : : : :: : ::: : : : : :: : :: : :::: : :::: :::: : : : :: :: : : : : : :::: :::: : : ::: :::: : :: : : : : : : :: ::: :::: : 2- 2- - - Lone Pair Bonding Pair E L E C T R O N C H A R G E C E N T E R : : : : Geometry 6 bond pair Bond angle - 90° Octahedral ✓ Geometry 5 bond pair 1 lone pair Bond angle < 90° ✓
  29. 29. Square planar F S SF6 F F F F F PCI6 - P CI CI CI CI CI CI IF5O I O || F F F F F F  S F  F F F F CI P CI   CI CI CI CI I F F F  F F :: O Square pyrimidal  CI Sb Sb CI CI CICI CI CI CICI CI (SbCI5)2- BrF5 Xe F FF F XeF4 F Br F FF F F Br  F F O F F Xe || F FF F O :: Xe F F F F F Te F FF F F  Te F F F F XeOF4 (TeF5)- - - CICI I CICI (ICI4)- - : : : : : : :: : : : :: ::: : :: : :::: :: : : : : : : : :: : : : : :: : ::: : : : : :: : :: : :::: : :::: :::: : : : :: :: : : : : : :::: :::: : : ::: :::: : :: : : : : : : :: ::: :::: : 2- 2- : - - Lone Pair Bonding Pair :: :: : :::: :::: : : : : : : : : : : :: :: : E L E C T R O N C H A R G E C E N T E R : : : : Geometry 6 bond pair Bond angle - 90° Octahedral ✓ Geometry 5 bond pair 1 lone pair Bond angle < 90° ✓ 4 bond pair 2 lone pair Bond angle - 90° ✓
  30. 30. Square planar F S SF6 F F F F F PCI6 - P CI CI CI CI CI CI IF5O I O || F F F F F F  S F  F F F F CI P CI   CI CI CI CI I F F F  F F :: O Square pyrimidal  CI Sb Sb CI CI CICI CI CI CICI CI (SbCI5)2- BrF5 Xe F FF F Xe XeF4 F F F Br F FF F F Br  F F O F F Xe || F FF F O :: Xe F F F F F Te F FF F F  Te F F F F XeOF4 (TeF5)- - - CICI I CICI (ICI4)- - : : : : : : :: : : : :: ::: : :: : :::: :: : : : : : : : :: : : : : :: : ::: : : : : :: : :: : :::: : :::: :::: : : : :: :: : : : : : :::: :::: : : ::: :::: : :: : : : : : : :: ::: :::: : 2- 2- : - - Lone Pair Bonding Pair :: :: : :::: :::: : : : : : : : : : : :: :: : (XeF3) - F E L E C T R O N C H A R G E C E N T E R Lone pair in equatorial first, then axial : : : : - Minimise repulsion Geometry 6 bond pair Bond angle - 90° Octahedral ✓ Geometry 5 bond pair 1 lone pair Bond angle < 90° ✓ 4 bond pair 2 lone pair Bond angle - 90° ✓ 3 bond pair 3 lone pair Bond angle - <90° T shape ✓
  31. 31. Linear Square planar F S SF6 F F F F F PCI6 - P CI CI CI CI CI CI IF5O I O || F F F F F F  S F  F F F F CI P CI   CI CI CI CI I F F F  F F :: O Square pyrimidal  CI Sb Sb CI CI CICI CI CI CICI CI (SbCI5)2- BrF5 Xe F FF F Xe XeF4 F F F Br F FF F F Br  F F O F F Xe || F FF F O :: Xe F F F F F Te F FF F F  Te F F F F XeOF4 (TeF5)- - - CICI I CICI (ICI4)- - : : : : : : :: : : : :: ::: : :: : :::: :: : : : : : : : :: : : : : :: : ::: : : : : :: : :: : :::: : :::: :::: : : : :: :: : : : : : :::: :::: : : ::: :::: : :: : : : : : : :: ::: :::: : 2- 2- : - - Lone Pair Bonding Pair :: :: : :::: :::: : : : : : : : : : : :: :: : (XeF3) - F (XeF2)2- F F Xe E L E C T R O N C H A R G E C E N T E R Lone pair in equatorial first, then axial Lone pair in equatorial first, then axial : : : : - 2- Minimise repulsion Minimise repulsion Geometry 6 bond pair Bond angle - 90° Octahedral ✓ Geometry 5 bond pair 1 lone pair Bond angle < 90° ✓ 4 bond pair 2 lone pair Bond angle - 90° ✓ 3 bond pair 3 lone pair Bond angle - <90° T shape ✓ 2 bond pair 4 lone pair Bond angle - 180° ✓
  32. 32. H O OO C BeH N B  X  x C SO O C H NO C OO CH N HH Be N OX x  X X  X  X  X X  X  x X x + + : F F F H H O O O C O O O B X F F F C H H x x O S O O C O x x O 2- 2- O x x : || BF3 CH2 O SO3 CO3 2- CO2 HCN BeH2 NO2 +Lone Pair Bonding Pair = = E L E C T R O N C H A R G E C E N T E R O3 O O O : O O : O NO2  N OO  N OO NO2 - N OO : N OO : SO2 OO - - S : S OO : E L E C T R O N C E N T E R
  33. 33. H Bond angle 104.5° Bond angle 180° O OO C BeH N B  X  x C SO O C H NO C OO CH N HH Be N OX x  X X  X  X  X X  X  x X x + + : F F F H H O O O C O O O B X F F F C H H x x O S O O C O x x O 2- 2- O x x : || BF3 CH2 O SO3 CO3 2- CO2 HCN BeH2 NO2 +Lone Pair Bonding Pair = = Bond angle 120° E L E C T R O N C H A R G E C E N T E R O3 O O O : O O : O NO2  N OO  N OO NO2 - N OO : N OO : SO2 OO - - S : S OO : E L E C T R O N C E N T E R
  34. 34. H Bond angle 104.5° Linear Bond angle 180° O OO C BeH N B  X  x C SO O C H NO C OO CH N HH Be N OX x  X X  X  X  X X  X  x X x + + : F F F H H O O O C O O O B X F F F C H H x x O S O O C O x x O 2- 2- O x x : || BF3 CH2 O SO3 CO3 2- CO2 HCN BeH2 NO2 +Lone Pair Bonding Pair ECC = 2 2 bond pair ✓ = = ECC = 3 3 bond pair Bond angle 120° Trigonal planar ✓ E L E C T R O N C H A R G E C E N T E R O3 O O O : O O : O NO2  N OO  N OO NO2 - N OO : N OO : SO2 OO - - S : S OO : ECC = 3 2 bond pair 1 lone pair Bent ✓ E L E C T R O N C E N T E R Equal repulsion Electron Distribution (LINEAR) Equal repulsion Electron Distribution (TRIGONAL PLANAR) Unequal repulsion Electron Distribution (TRIGONAL PLANAR)
  35. 35. O N H N : : O SO3 2-PH3NH3 O HH H2O H H O O F2O F F F F O S CICI SCI2 N H H S CI CI N H NH2 - - - H: : : : : : : : : : : CIO3 - H H P H H H H H H P H H H : O O S O S O : O 2- 2- CI O O O CI : O O - : CH4 C H NH4 + BH4 - PCI4 + H H H H C H H H  N H H H H H N H H H  H B HH H H B H  H H CI CI CI CI P CI CI CI P  CI - - + + + + :: : :: :: : : :: : : : : : Lone Pair Bonding Pair E L E C T R O N C H A R G E C E N T E R -
  36. 36. Bond angle 109.5° Bond angle 104.5° O Bond angle 107° N H N : : O SO3 2-PH3NH3 O HH H2O H H O O F2O F F F F O S CICI SCI2 N H H S CI CI N H NH2 - - - H: : : : : : : : : : : CIO3 - H H P H H H H H H P H H H : O O S O S O : O 2- 2- CI O O O CI : O O - : CH4 C H NH4 + BH4 - PCI4 + H H H H C H H H  N H H H H H N H H H  H B HH H H B H  H H CI CI CI CI P CI CI CI P  CI - - + + + + :: : :: :: : : :: : : : : : Lone Pair Bonding Pair E L E C T R O N C H A R G E C E N T E R -
  37. 37. Bond angle 109.5° Bond angle 104.5° O Bond angle 107° Tetrahedral Trigonal Pyrimidal N H N : : O SO3 2-PH3NH3 O HH H2O H H O O F2O F F F F O S CICI SCI2 N H H S CI CI N H NH2 - - - H: : : : : : : : : : : Bent CIO3 - H H P H H H H H H P H H H : O O S O S O : O 2- 2- CI O O O CI : O O - : CH4 C H NH4 + BH4 - PCI4 + H H H H C H H H  N H H H H H N H H H  H B HH H H B H  H H CI CI CI CI P CI CI CI P  CI - - + + + + :: : :: :: : : :: : : : : : Lone Pair Bonding Pair E L E C T R O N C H A R G E C E N T E R 2 bond pair 2 lone pair ECC = 4 3 bond pair 1 lone pair ✓ ECC = 4 4 bond pair ✓ - ✓ ECC = 4 Electron Distribution (TETRAHEDRAL) Unequal repulsion Unequal repulsion Electron Distribution (TETRAHEDRAL) Equal repulsion Electron Distribution (TETRAHEDRAL)
  38. 38. P CICI CI CI CI : P  CI  CI CI CI   S F F F F S F   F F F Te CI CI CI CI Te CI CI CI CI : CI F F F CI F  F F  I CI CI CI CI I   CI  CI I F F F F F I  F F  F Xe F F O O Xe  F  F O O : + + : CI   I I I   Xe CI CI I  F F  ::::::: : : :: :: :: : : : : : :: : : :: : : : : : :: :: : :::: : : :: : :: : :: :: : :: : :: : :: :: :: :: :: :: :: :: :: : : : : BrF F F Br F    F F : : : : : : :: : - PCI5 SF4 TeCI4 (IF4)+ XeO2F2 CIF3 ICI3 BrF3 (I3)- (ICI2)- XeF2 - Bonding Pair Lone Pair E L E C T R O N C H A R G E C E N T E R : : : : F F Xe F F Xe  F F :: : :: :: :: + +
  39. 39. Bond angle 180° Bond angle <90° Bond angle < 90° , < 120° Bond angle 90° , 120° P CICI CI CI CI : P  CI  CI CI CI   S F F F F S F   F F F Te CI CI CI CI Te CI CI CI CI : CI F F F CI F  F F  I CI CI CI CI I   CI  CI I F F F F F I  F F  F Xe F F O O Xe  F  F O O : + + : CI   I I I   Xe CI CI I  F F  ::::::: : : :: :: :: : : : : : :: : : :: : : : : : :: :: : :::: : : :: : :: : :: :: : :: : :: : :: :: :: :: :: :: :: :: :: : : : : BrF F F Br F    F F : : : : : : :: : - PCI5 SF4 TeCI4 (IF4)+ XeO2F2 CIF3 ICI3 BrF3 (I3)- (ICI2)- XeF2 - Bonding Pair Lone Pair E L E C T R O N C H A R G E C E N T E R : : : : F F Xe F F Xe  F F :: : :: :: :: + +
  40. 40. Bond angle 180° Linear Bond angle <90° T shape Bond angle < 90° , < 120° Trigonal BipyrimidalBond angle 90° , 120° P CICI CI CI CI : P  CI  CI CI CI   S F F F F S F   F F F Te CI CI CI CI Te CI CI CI CI : CI F F F CI F  F F  I CI CI CI CI I   CI  CI I F F F F F I  F F  F Xe F F O O Xe  F  F O O : + + : CI   I I I   Xe CI CI I  F F  ::::::: : : :: :: :: : : : : : :: : : :: : : : : : :: :: : :::: : : :: : :: : :: :: : :: : :: : :: :: :: :: :: :: :: :: :: : : : : BrF F F Br F    F F : : : : : : :: : - PCI5 SF4 TeCI4 (IF4)+ XeO2F2 CIF3 ICI3 BrF3 (I3)- (ICI2)- XeF2 - Bonding Pair Lone Pair E L E C T R O N C H A R G E C E N T E R : : : : ECC = 5 5 bond pair ✓ ECC = 5 4 bond pair 1 lone pair Seesaw ✓ ECC = 5 3 bond pair 2 lone pair ✓ ECC = 5 2 bond pair 3 lone pair F F Xe F F Xe  F F :: : :: :: :: + + ✓ Equal repulsion Electron Distribution (TRIGONAL BIPYRIMIDAL) Unequal repulsion Electron Distribution (TRIGONAL BIPYRIMIDAL) Unequal repulsion Electron Distribution (TRIGONAL BIPYRIMIDAL) Electron Distribution (TRIGONAL BIPYRIMIDAL)
  41. 41. F S SF6 F F F F F PCI6 - P CI CI CI CI CI CI IF5O I O || F F F F F F  S F  F F F F CI P CI   CI CI CI CI I F F F  F F :: O  CI Sb Sb CI CI CICI CI CI CICI CI (SbCI5)2- BrF5 Xe F FF F Xe XeF4 F F F Br F FF F F Br  F F O F F Xe || F FF F O :: Xe F F F F F Te F FF F F  Te F F F F XeOF4 (TeF5)- - - CICI I CICI (ICI4)- - : : : : : : :: : : : :: ::: : :: : :::: :: : : : : : : : :: : : : : :: : ::: : : : : :: : :: : :::: : :::: :::: : : : :: :: : : : : : :::: :::: : : ::: :::: : :: : : : : : : :: ::: :::: : 2- 2- : - - Lone Pair Bonding Pair :: :: : :::: :::: : : : : : : : : : : :: :: : (XeF3) - F (XeF2)2- F F Xe E L E C T R O N C H A R G E C E N T E R Lone pair in equatorial first, then axial Lone pair in equatorial first, then axial : : : : - 2- Minimise repulsion Minimise repulsion
  42. 42. F S SF6 F F F F F PCI6 - P CI CI CI CI CI CI IF5O I O || F F F F F F  S F  F F F F CI P CI   CI CI CI CI I F F F  F F :: O  CI Sb Sb CI CI CICI CI CI CICI CI (SbCI5)2- BrF5 Xe F FF F Xe XeF4 F F F Br F FF F F Br  F F O F F Xe || F FF F O :: Xe F F F F F Te F FF F F  Te F F F F XeOF4 (TeF5)- - - CICI I CICI (ICI4)- - : : : : : : :: : : : :: ::: : :: : :::: :: : : : : : : : :: : : : : :: : ::: : : : : :: : :: : :::: : :::: :::: : : : :: :: : : : : : :::: :::: : : ::: :::: : :: : : : : : : :: ::: :::: : 2- 2- : - - Lone Pair Bonding Pair :: :: : :::: :::: : : : : : : : : : : :: :: : (XeF3) - F (XeF2)2- F F Xe E L E C T R O N C H A R G E C E N T E R Lone pair in equatorial first, then axial Lone pair in equatorial first, then axial : : : : - 2- Minimise repulsion Minimise repulsion Bond angle 90° Bond angle < 90° Bond angle < 90° Bond angle 180° Bond angle 90°
  43. 43. Linear Square planar F S SF6 F F F F F PCI6 - P CI CI CI CI CI CI IF5O I O || F F F F F F  S F  F F F F CI P CI   CI CI CI CI I F F F  F F :: O Square pyrimidal  CI Sb Sb CI CI CICI CI CI CICI CI (SbCI5)2- BrF5 Xe F FF F Xe XeF4 F F F Br F FF F F Br  F F O F F Xe || F FF F O :: Xe F F F F F Te F FF F F  Te F F F F XeOF4 (TeF5)- - - CICI I CICI (ICI4)- - : : : : : : :: : : : :: ::: : :: : :::: :: : : : : : : : :: : : : : :: : ::: : : : : :: : :: : :::: : :::: :::: : : : :: :: : : : : : :::: :::: : : ::: :::: : :: : : : : : : :: ::: :::: : 2- 2- : - - Lone Pair Bonding Pair :: :: : :::: :::: : : : : : : : : : : :: :: : (XeF3) - F (XeF2)2- F F Xe E L E C T R O N C H A R G E C E N T E R Lone pair in equatorial first, then axial Lone pair in equatorial first, then axial : : : : - 2- Minimise repulsion Minimise repulsion ECC = 6 6 bond pair Bond angle 90° Octahedral ✓ ECC = 6 5 bond pair 1 lone pair Bond angle < 90° ✓ 4 bond pair 2 lone pair ✓ 3 bond pair 3 lone pair Bond angle < 90° T shape ✓ 2 bond pair 4 lone pair Bond angle 180° ✓ Equal repulsion Electron Distribution (OCTAHEDRAL) Unequal repulsion Electron Distribution (OCTAHEDRAL) Bond angle 90° Electron Distribution (OCTAHEDRAL) Electron Distribution (OCTAHEDRAL) Unequal repulsion Electron Distribution (OCTAHEDRAL)
  44. 44. Valence Shell Electron Pair Repulsion Predict molecular shape/geometry Shape determine by electron pairs/ electron charge centers/ECC Bonding/lone pair – repel each other Bonding/lone pair arrange themselves as far as possible (minimise repulsion) Valence Shell Electron Pair Repulsion N H HH .. Principles of VSEPR Shape of molecule Determine number valence e around central atom1 2 Single, double, triple bond , lone pair act as electron charge center/ECC 3 4 Lone pair-lone pair > Lone pair-bonding pair > bonding pair-bonding pair repulsion 5 6 ECC or electron pair position in equatorial first, then axial Lewis structure VSEPR .. N H H H Geometry 4 ECC 3 bonding pair 1 lone pair Trigonal pyrimidal 1 2 3 Bond pair electron • Occupy smaller region space bet nuclei • Repulsion less Lone pair electron nucleus > Bonding pair electron Concept Map nuclei Lone pair electron • Electron pair occupy greater space • Repel any bonding pair nearby • Lone pair repulsion > bonding pair repulsion Double bond •Repulsion greater •Angle smaller, 111.4° B F F F Single bond •Equal repulsion •Angle 120° 120° 120° 120° space occupy by electron space occupy by electron
  45. 45. Acknowledgements Thanks to source of pictures and video used in this presentation Thanks to Creative Commons for excellent contribution on licenses http://creativecommons.org/licenses/ Prepared by Lawrence Kok Check out more video tutorials from my site and hope you enjoy this tutorial http://lawrencekok.blogspot.com
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