Chapter 9

1. Chapter 9 MoCu

2. VSEPR Theory Electron pairs around a central atom arrange themselves so that they can be as far apart as possible from each other.

3. Polarity • When two atoms bond, a dipole moment occurs. If both atoms are of even size and have the same charge, the dipole moment will be zero. • EX: CO2 • When a molecule forms, if two dipole moments with polarity are opposite, the molecule is not polar, if they are not directly opposite the molecules are polar.

4. Linear - Electron-Domain Geometry • Molecular: Linear • Domains: 2 Total • All bonding pairs • Bond Angles: 180o • Hybridization: sp • Polar? No

5. Trigonal Planar - Electron-Domain Geometry • Molecular: trigonal planar • Domains: 3 Total • All bonding pairs • Bond Angles: 120o • Hybridization: sp2 • Polar? No

6. Trigonal Planar - Electron-Domain Geometry • Molecular: bent • Domains: 3 Total • 2 bonding pairs • 1 nonbonding pair • Bond Angles: 120o • Hybridization: sp2 • Polar? Yes

7. Tetrahedral - Electron-Domain Geometry • Molecular: Tetrahedral • Domains: 4 Total • All bonding pairs • Bond Angles: 109.5o • Hybridization:sp3 • Polar? No

8. Tetrahedral- Electron-Domain Geometry • Molecular: Trigonal Pyramidal • Domains: 4 Total • 3 bonding pairs • 1 nonbonding pair • Bond Angles: 109.5o • Hybridization: sp3 • Polar? Yes

9. Tetrahedral - Electron-Domain Geometry • Molecular: Bent • Domains: 4 Total • 2 bonding pairs • 2 nonbonding pairs • Bond Angles: 109.5o • Hybridization:sp3 • Polar? Yes

10. Trigonal Bipyramidal- Electron-Domain Geometry Molecular: Trigonal Bipyramidal Domains: 5 Total All bonding pairs Bond Angles: 120o,90o Hybridization: sp3d Polar? No

11. Trigonal Bipyramidal- Electron-Domain Geometry Molecular: Seesaw Domains: 5 Total 4 bonding domains 1 nonbonding domains Bond Angles: 120o,90o Hybridization: sp3d Polar? Yes

12. Trigonal Bipyramidal- Electron-Domain Geometry Molecular: T-shaped Domains: 5 Total 3 bonding domains 2 nonbonding domains Bond Angles: 120o,90o Hybridization: sp3d Polar? Yes

13. Trigonal Bipyramidal- Electron-Domain Geometry Molecular: Linear Domains: 5 Total 4 bonding domains 1 nonbonding domains Bond Angles: 120o,90o Hybridization: sp3d Polar? Yes

14. Octahedral- Electron Domain Geometry Molecular: Octahedral Domains: 6 Total 6 bonding domains 0 nonbonding domains Bond Angles: 90o Hybridization: sp3d2 Polar? No

15. Octahedral- Electron Domain Geometry Molecular: Square Pyramidal Domains: 6 Total 5 bonding domains 1 nonbonding domains Bond Angles: 90o Hybridization: sp3d2 Polar? Yes

16. Octahedral- Electron Domain Geometry Molecular: Square Planar Domains: 6 Total 4 bonding domains 2 nonbonding domains Bond Angles: 90o Hybridization: sp3d2 Polar? No

17. Sigma Bond Pi Bond covalent bond in which electron density is concentrated along the internuclear axis. Electron densities overlap Strongest type of covalent bond covalent bond in which electron density is concentrated above and below the internuclear axis. Weaker than sigma bonds

18. Problems 1. What are the electron-domain and molecular geometries of a molecule that has the following electron domains on its central atom? A) 4 bonding, 0 non bonding B) 3 bonding, 1 non bonding C) 2 bonding, 2 non bonding

19. Problems 2. Do the electron-domain and molecular geometry, bond angles, polarity, hybridization and resonance structures for: A) KrF2 B) SiCl4 C) BCl3