Molecular Shapes Lewis structures physical properties VSEPR (b.p., solubility) polarity separation of charge in molecule electronegativity HF + -
electronegativity larger molecules molecular shape CO2 b.p. = -78oC SO2 b.p. = 23oC : : : : : : : : : O C O : : : : O S O : : : : 2 valence pairs linear 3 valence pairs trigonal + + - - - - non-polar
CHCl3 CCl4 water soluble insoluble C H Cl C Cl 4 valence pairs tetrahedral non-polar polar
Valence Bond Theory covalent bond overlap of orbitals bonding e- pair opposite spins CH4 geometry tetrahedral [He] 2s2 2p2 shape tetrahedral Pauling valence e- orbitals in molecules in atoms mix produce molecular orbitals
sp3 mixing hybridization depends on number of atomic orbitals mixed type of atomic orbitals mixed CH4 need equivalent orbitals 4 mix atomic orbitals 4 [He] 2s2 2p2 mix s and 3 p sp3
sp3 CH4 hydrogen sigma bond [He] 2s2 2p2 bond sp3 p energy hybridization sp3 s CH4 hydrogen sigma bond [He] 2s2 2p2 s bond sp3
sp2 formaldehyde CH2O C : H O 3 valence pairs on C 3 hybrid orbitals [He] 2s2 2p2 sp 2
sp2 -bond -bond : C H O p p energy hybridization sp2 s p p energy
sp CO2 C :: O : 2 hybridized bonds 2 unhybridized bonds s + p sp
sp C : :: C O -bond end-to-end -bond side-to-side O p p energy hybridization C sp s C :: O : -bond end-to-end -bond side-to-side p p energy hybridization O sp2 s
PCl5 trigonal bipyramidal P Cl 5 hybridized orbitals 5 mix s + 3p + d dsp3
SF6 octahedral S F 6 hybridized orbitals 6 mix s + 3p + 2d d2sp3