Molecular Structure VSEPR Model. VSEPR Valence Shell Electron Pair Repulsion The structure around a...

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Molecular Structure VSEPR Model

Transcript of Molecular Structure VSEPR Model. VSEPR Valence Shell Electron Pair Repulsion The structure around a...

Page 1: Molecular Structure VSEPR Model. VSEPR Valence Shell Electron Pair Repulsion The structure around a given atom is determined principally by minimizing.

Molecular StructureVSEPR Model

Page 2: Molecular Structure VSEPR Model. VSEPR Valence Shell Electron Pair Repulsion The structure around a given atom is determined principally by minimizing.

VSEPRValence Shell Electron Pair Repulsion

The structure around a given atom is determined principally by minimizing electron-pair repulsions

Non-bonding and bonding electrons pairs will be as far apart as possible

Page 3: Molecular Structure VSEPR Model. VSEPR Valence Shell Electron Pair Repulsion The structure around a given atom is determined principally by minimizing.

Examples CO2

• BF3

CH4

Page 4: Molecular Structure VSEPR Model. VSEPR Valence Shell Electron Pair Repulsion The structure around a given atom is determined principally by minimizing.

Effect of Unshared Electron Pairs

The ideal tetrahedral angle is 109.5°

Lone (unshared) electron pairs require more room than bonding pairsThey have greater repulsive forcesTend to compress the angles between bonding

pairs

Lone pairs do not cause distortion when bond angles are 120° or greater

Page 5: Molecular Structure VSEPR Model. VSEPR Valence Shell Electron Pair Repulsion The structure around a given atom is determined principally by minimizing.

Multiple BondsMultiple bonds count as one effective electron

pair

When a molecule exhibits resonance, ANY of the resonance structures can be used to predict the molecular structure using the VSEPR model

Page 6: Molecular Structure VSEPR Model. VSEPR Valence Shell Electron Pair Repulsion The structure around a given atom is determined principally by minimizing.

No Single Central AtomApply the principal of distancing shared and

unshared electron pairs

Look at real 3D models to develop predictive skills

Page 7: Molecular Structure VSEPR Model. VSEPR Valence Shell Electron Pair Repulsion The structure around a given atom is determined principally by minimizing.

VSEPR ModelsFor non-ionic compounds –

works in most cases