# of regionsbond anglehybridizationLecture3 Outline of Last Lecture I. Recognizing patterns for drawing resonance structuresII. Things not to do when creating resonance structuresCHEM 333 1st EditionIII. s and p orbitalsElectrons as wavesHybridizationsp3 orbitalsOutline of Current Lecture I. sp2 orbitalsI. sp orbitalsII. How to identify hybridization of each atomIII. Combine resonance and hybridizationIV. Bond angles/3D and bond polarityCurrent LectureI. sp2 orbitals: 1s + 2p -> 3sp2A. Example: Has one left over, unhybridized p orbitalII. sp orbitals: s + p -> 2 sp orbitals and 2 unhbyridized orbitals remainingA. Example:III. How to idenitfy hybridization of each atom# of regions bond angle hybridization1 --- s2 180° sp3 120° sp24 109.5° sp3IV. Combine resonance and hybridizationA. Example: N has four regions of electron density, but it is sp2, not sp3, because if a lone pair can be involved in resonance, it needs to be in a p orbital. (If it looks sp3, take off one p so that it is sp2.)B. Example: O is sp2 because you move a lone pair so that it is -O- with one lone pair on topC. Example: O is sp3 because you cannot move a lone pair so it is -O- with two lone pairsD. Strength: triple bond > double bond > single bondE. Length: triple bond < double bond < single bonda. The shorter the bond is, the stronger it is.V. Bond angles/3D and bond polarityA. Polar molecule:a. Must have polar bondsb. Depends on arrangement of polar bondsA. Molecular dipole: vector sum of bond dipolesa. Examples: The more polar something is, the greater molecular dipole ) is. = 0 when molecule is nonpolar.(�
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