CHEM1101 Lecture Notes - Lecture 5: Trigonal Pyramidal Molecular Geometry, Trigonal Bipyramidal Molecular Geometry, Vsepr Theory
When an element is in period 3 or below in the periodic table (3, 4, 5, 6, etc.), I can use d-orbitals to made more
than 4 binds
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Why does SF₆ occur but OF₆ doesn’t
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SF₆ has a d-orbital
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REMEMBER look at the quantum number l to determine which contain d-orbitals
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SF₆ is a hypervalent compound
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Example: SF₆
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Draw the Lewis structure for IF₂⁻
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More than 8 electrons
Daw an octet obeying Lewis structure for ClO₃⁻
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Lecture 5
01 March 2017
12:00
CHEM1101 Page 1
Document Summary
When an element is in period 3 or below in the periodic table (3, 4, 5, 6, etc. ), i can use d -orbitals to made more than 4 binds. Remember look at the quantum number l to determine which contain d-orbitals. Daw an o(cid:272)tet o(cid:271)eying lewis stru(cid:272)ture for clo(cid:1032) . Electron pairs (bonding or lone) repel each other. Assume that the e- pairs are as far away from each other as possible, this assists us in predicting the shape of the molecule. This is the valence-shell electron-pair repulsion (vsepr) model. Refer to electron directions to which electron points as electron domains. The central atom in this molecule, a, has 4 domains. To determine the electron-domain geometry, count the total no. of lone pairs, signal, double and triple bonds on the central atom. Chem1101 page 2 triple bonds on the central atom. In a double bond, the electron density is higher, so it would affect the bond angle slightly.
