4.2 - Vsepr Theory - chemistry PDF

Title	4.2 - Vsepr Theory - chemistry
Author	Shae Antonides
Course	Biology for Science II
Institution	The University of Western Ontario
Pages	5
File Size	253.7 KB
File Type	PDF
Total Downloads	29
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Summary

chemistry ...

Description

4.2 – Three-Dimensional Structure (VSEPR Theory) V S E P R

valence shell electron pair repulsion

 This theory predicts the geometric shape of molecules. It is based on the understanding that electron pairs around the central atom in a molecule will situate themselves as far apart as possible because of the forces of repulsion that exist between particles of like charges.

A - central atom X - bonding pairs of electrons on the central atom E - nonbonding pairs of electrons on the central atom  These symbol’s values are determined by drawing the Lewis structure for a molecule and combined to create the molecule’s VSEPR formula. Once the formula has been determined the electron arrangement, molecular geometry (shape), bond angles can be predicted.

Try these: H2O

TeF4

VSEPR formula: ________

VSEPR formula: ________

FCl2+

BrF4 -

VSEPR formula: ________

VSEPR formula: ________

Main VSEPR Formulas

Formula

Bonding Pairs

Nonbonding Pairs

Total Pairs

Electron Pair Arrangement

Molecular Geometry

AX2

2

0

2

linear

linear

AX3

3

0

3

AX4

4

0

4

AX5

5

0

5

90/120°

AX6

6

0

6

90°

VSEPR

Try these:

Diagram

Bond Angles

180°

120°

tetrahedral

tetrahedral

109.5°

VSEPR Formula

Bonding Nonbonding Pairs Pairs

Total Pairs

Electron Pair Arrangement

Molecular Geometry

Diagram

SbF5

CO2

AsCl6-

SO3

CCl4

VSEPR Theory – Summary Chart VSEPR Formula

Total Pairs

Electron Pair Arrangement

Molecular Geometry

Bond Angles

Ex.

AX2

2

linear

linear

180º

BeCl2

3D diagram

Bond Angles

AX3

3

trigonal planar

trigonal planar

120º

BeH3

AX2E

3

trigonal planar

bent

120º

SnCl2

AX4

4

tetrahedral

tetrahedral

109.5

CH4

AX3E

4

tetrahedral

trigonal pyramidal

< 109.5

NH3

AX2E2

4

tetrahedral

bent

< 109.5

H2O

AX5

5

trigonal bypyramidal

trigonal bypyramidal

90/120º

PCl5

trigonal bypyramidal

seesaw

90/180º

SF4

trigonal bypyramidal

T-shaped

90/180º

ClF3

5 AX4E 5 AX3E2

AX2E3

5

trigonal bypyramidal

linear

180º

ICl2

VSEPR Formula

Total Pairs

Electron Pair Arrangement

Molecular Geometry

Bond Angles

Ex.

AX6

6

octahedral

octahedral

90º

SF6

3D diagram

6 AX5E

AX4E2

6

octahedral

square pyramidal

90º

BrF5

octahedral

square planar

90º

XeF4...