Molecular Geometry and

Polarity

Molecular Shapes

OMolecular shape determines chemical and physical properties

OElectrons repel each other resulting in the molecular shape

OLone pairs are not shared between protons and therefore repel slightly more

OAtomic orbitals mix to form new identical orbitals

Hybridization

Determine Molecular Geometry and Hybridization

OBF3

ONH4+

OOCl2OBeF2

OCF4

OCS2

OCCl2F2

ONCl3

Bond Polarity OUnequal sharing of electrons due to differences in electronegativity

0 - 0.4 0.5 - 1.7 Above 1.7

Molecular Polarity

Molecular Polarity

OMolecules that are symmetrical tend to be nonpolar covalent molecules

OMolecular Dipole-the overall direction of pull on the molecule

PHET Simulation

ODraw the following molecules and label the dipole of the moleculeHF F2 H2O

CO2 NH3 CH2O

CH4 CH2F2 CHCl3

Properties of Covalent Compounds

OLow melting and boiling points

Properties of Covalent Compounds

OMany molecules exist as gases

OSoft solidsOParaffin

Properties of Covalent Compounds

OPoor Conductors of Electricity

Review Problems: pg. 272

#72, 84, 89-92, 95, 96, 97 (a-c), 98 (a, c), 99, 102, 104, 105-117odds