Chemical Bonding and Interactions The Ties That Bind Chemical Bonding and Interactions

Chemical Bonding and Interactions Stable Electron Configurations Electron-Dot (Lewis) Structures Drawing, Rules for Drawing The Octet Rule Some Exceptions to the Rule Ionic Bonding Naming ionic compounds Drawing Covalent Bonding Naming covalent compounds Electronegativity and Polar Covalent Compounds Molecular Shapes and the VSEPR Theory Intermolecular Forces of Attraction H-bonds, Dipole-Dipole, Ion-Dipole, London Dispersion Forces

MOLECULAR GEOMETRY

The VSEPR Model Predicting Molecular Geometries

0 lone pairs on central atom 2 atoms bonded to central atom Cl Be 0 lone pairs on central atom 2 atoms bonded to central atom 10.1

10.1

The VSEPR Model Predicting Molecular Geometries

10.1

bonding-pair vs. bonding pair repulsion lone-pair vs. lone pair repulsion lone-pair vs. bonding >

The VSEPR Model Molecules with Expanded Valence Shells

The VSEPR Model Molecules with Expanded Valence Shells To minimize e--e- repulsion, lone pairs are always placed in equatorial positions.

The VSEPR Model Molecules with Expanded Valence Shells

10.1

10.1

10.1

The VSEPR Model

The VSEPR Model Molecules with More than One Central Atom In acetic acid, CH3COOH, there are three central atoms. We assign the geometry about each central atom separately.

Predicting Molecular Geometry Draw Lewis structure for molecule. Count number of lone pairs on the central atom and number of atoms bonded to the central atom. Use VSEPR to predict the geometry of the molecule. What are the molecular geometries of SO2 and SF4? S F S O AB4E AB2E distorted tetrahedron bent 10.1

The VSEPR Model Predicting Molecular Geometries To determine the electron pair geometry: draw the Lewis structure; count the total number of electron pairs around the central atom. arrange the electron pairs in one of the above geometries to minimize e--e- repulsion. multiple bounds count as one bonding pair.