molecular geometry memorize shape
TRANSCRIPT
Molecular Geometry Memorize Shape Electron Density Regions 2 3 3 4 4 4 5 5 5 5 6 6 Lone Pairs 0 0 1 0 1 2 0 1 2 3 0 1 Example CO2 BF3 SO2 CH4 NH3 H2O PF5 SF4 ICl3 I3SCl6 XeF5+ Molecular Geometry (Bond Angles) Linear (180) Trigonal Planar (120) Bent (117) Tetrahedral (109.5) Trigonal Pyramidal (107) Bent (105) Trigonal Bipyramidal See Saw T-shaped Linear Octahedral Square Pyramidal Hybridization sp sp2 sp2 sp3 sp3 sp3 sp3d sp3d sp3d sp3d sp3d2 sp3d2
**Base geometries in bold print 1. Once you are able to predict geometry, it is then possible to understand polarity of molecules - polarity refers to the uneven sharing of electrons in a covalent bond - polarity can lead to polar molecules - all polar molecules must contain polar bonds - some nonpolar molecules can contain polar bonds - dipole moments (difference between electronegativities) can be added together as vector quantities to determine the net polarity of a molecule 2. polarity is important because it too (like the geometry of the molecule) determines how a molecule will interact with other molecules
II.
Hybridization of Orbitals Based on carbons electron configuration and the fact that only lone electrons in an orbital can contribute to covalent bonding, how then does carbon create four single bonds? ANSWER: the electron configuration does not explain the bonding properties of carbon; only, hybridization can explain how carbon forms its four single bonds A. Hybridization 1. Hybridization of orbitals is the mixing of two or more atomic orbitals from similar energies on the same atom to produce new hybrid atomic orbitals of equal energy (degenerate orbitals) 2. hybridization of orbitals explains carbon (and other atoms) bonding properties 3. Hybrid orbitals are what we call the degenerate orbitals 4. for hybrid orbitals, the number of hybrid orbitals produced is equal to the number of orbitals combined to create them 5. Types of hybrid orbitals: Combining Orbitals s,p s,p,p s,p,p,p s,p,p,p,d s,p,p,p,d,d Type of Hybridization sp sp2 sp3 sp3d sp3d2 Number of Hybrid orbitals 2 3 4 5 6 Base Geometry Shape Linear Trigonal planar Tetrahedral Trigonal bipyramidal Octahedral
6. hybridization can be determined by looking at the lewis structure of a cpd 7. to determine hybridization, simply count the electron density regions around an atom , the number of electron density regions is equal to the number of hybrid orbitals as noted above
Electron Density Regions 2
Lone Pairs 0
Example CO2
Molecular Geometry (Bond Angles) Linear (180)
Hybridization sp
Electron Density Regions 3
Lone Pairs 0
Example BF3
Molecular Geometry (Bond Angles) Trigonal Planar (120)
Hybridization sp2
Electron Density Regions 3
Lone Pairs 1
Example SO2
Molecular Geometry (Bond Angles) Bent (117)
Hybridization sp2
Electron Density Regions 4
Lone Pairs 0
Example CH4
Molecular Geometry (Bond Angles) Tetrahedral (109.5)
Hybridization sp3
Electron Density Regions 4
Lone Pairs 1
Example NH3
Molecular Geometry (Bond Angles) Trigonal Pyramidal (107)
Hybridization sp3
Electron Density Regions 4
Lone Pairs 2
Example H2O
Molecular Geometry (Bond Angles) Bent (105)
Hybridization sp3
Electron Density Regions 5
Lone Pairs 0
Example PF5
Molecular Geometry (Bond Angles) Trigonal Bipyramidal
Hybridization sp3d
Electron Density Regions 5
Lone Pairs 1
Example SF4
Molecular Geometry (Bond Angles) See Saw
Hybridization sp3d
Electron Density Regions 5
Lone Pairs 2
Example BrF3
Molecular Geometry (Bond Angles) T-shaped
Hybridization sp3d
Electron Density Regions 5
Lone Pairs 3
Example ICl2-
Molecular Geometry (Bond Angles) Linear
Hybridization sp3d
Electron Density Regions 6
Lone Pairs 0
Example PCl6-
Molecular Geometry (Bond Angles) Octahedral
Hybridization sp3d2
Electron Density Regions 6
Lone Pairs 1
Example XeF5+
Molecular Geometry (Bond Angles) Square Pyramidal
Hybridization sp3d2
Electron Density Regions 6
Lone Pairs 2
Example XeF4
Molecular Geometry (Bond Angles) Square Planar
Hybridization sp3d2