Download presentation

Presentation is loading. Please wait.

1
**Molecular Geometry and Bonding Theory**

Chapter 9 AP Chemistry

2
Molecular Geometry Molecular Geometry- general shape of a molecule as determined by the relative position of the nuclei. The geometry and size of a molecule helps to determine it’s chemical behavior. VSEPR- Valence-Shell-Electron-Pair-Repulsion model- predicts geometry based upon e’s around the central atom.

3
**Principles of the VSEPR theory**

Electrons are kept as far away from one another as possible – minimizing e pair repulsions Electron pairs are considered as being bonding or non-bonding (lone pairs) A multiple bond counts as a single bonding pair Electron pair geometry is described by the regions of e’s around the central atom Molecular geometry is a consequence of electron pair geometry.

4
**Predicting Structures VSEPR**

Derive the Lewis Structure to the form AXmEn A = central atom X = atoms bonded to the central atom E = lone pairs of e’s on the central atom M = # of bonded atoms N = # of lone pairs

5
**Electron Geometry Linear**

Example Electron and Molecular Geometry Linear Bond angles 180 Sp Hybrid Non-polar

6
More Examples AX2

7
**Electron Geom. Trigonal Planar**

Molecular Geom. Trigonal Planar bond angles exactly 120 non-polar Bent bond angles aprox 120 polar molecule Sp2 hybridized

8
**Electron Geom.Trigonal Planar**

Molecular Geometry: AX3 (3BP or 2BP + 1LP) ex. 3bp NO3- <>

9
Examples Cont. 3bp BF3 <> <>

10
Examples Cont. 2bp + 1 lp Ex O3 (ozone)

11
**Electron Geom. Tetrahedral**

Molecular Geom. Tetrahedral bond angles exactly non-polar molecule, Trigonal pyramidal bond angles aprox polar molecule, Bent bond angles aprox polar molecule Sp3 hybridized

12
**Molecular Geometry: AX4 [4BP or (3BP + 1LP) or (2BP + 2LP)]**

Electron Geometry: AX4 Tetrahedral

13
Example BrO3F, Perbromyl fluoride

14
**Molecular Geometry: AX3E1 Trigonal Pyramidal**

15
Example NF3, Nitrogen trifluoride

16
**Molecular Geometry: AX2E2 Bent/Angular**

17
Example H2O, Water, ClOF, Chlorosyl fluoride

18
**Electron Geom. Trigonal Bypyramidal**

Mol. Geom. Trigonal Bypyramidal – bond angles ax. exactly 108 deg. eq. exactly 120 deg. Non-polar, See-Saw – bond angles ax. aprox. 108 deg. eq. aprox. 120 deg. Polar, T-shaped - bond angles ax. aprox. 108 deg. No –eq, Linear – bond angle exactly 180 non-polar. All sp3d hybridized

19
**Mol geo. Trigonal bipramidal**

AX5 [5BP or (4BP + 1 LP) or (3BP + 2LP) or (2BP + 3LP)] 5bp

20
Example PCl5(gas phase), Phosphorous pentachloride

21
**Molecular Geometry: AX4E1 See-saw**

Example IF2O2-

22
**Molecular Geometry: AX3E2 T-structure**

Example ClF3

23
**Molecular Geometry: AX2E3 Linear**

Examole XeF2

24
**Electron Geometry Octahedrial**

Mol geo. Octahedral – bond angle exactly non-polar, square pyramidal – bond angle aprox 90- polar, square planar- bond angle exactly 90 non-polar Sp3d2 hybridized

25
**Molecular Geometry: AX6 Octahedral**

Example SF6

26
**Molecular Geometry: AX4E1 Pyramidal Planar**

Example XeOF4

27
**Molecular Geometry: AX4E2 Square Planar**

Example XeF4

28
Bond Angles Non-bonding pairs of e’s take up more space (att. by one nucli) than bonded e pairs Double and triple bonds take up more space than single bonds (more e’s) Volume occupied lone pairs > triple bonds > double bonds > single bonds

29
Forces Non-bonding pairs exert repulsive forces on adjacent e pairs and compress angles Multiple bonds also exert repulsive forces and compress angles

Similar presentations

OK

Chapter 9: Molecular Geometry and Bonding Theories What do the molecules look like and why?

Chapter 9: Molecular Geometry and Bonding Theories What do the molecules look like and why?

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on emotional intelligence in leadership Animated ppt on magnetism perfume Ppt on new technology in cse Presentation ppt on motivation and emotion Ppt on production planning and inventory control Ppt on different occupations for kids Thyroid anatomy and physiology ppt on cells Ppt on solar power air conditioning Ppt on course management system Ppt on fair and lovely