Lecture Notes #2

Lecture Notes for VSEPR & MO Theory
THE SHAPES OF SOME SIMPLE MOLECULES see Fig.1.7 & 1.8 text
Electronic Geometry describes the arangement of electrons about the central atom Molecular Geometry describes the arangement of atoms about the central atom
see Fig.1.9 text
Electron pairs repell each other. LP-LP>>LP-BP>BP-BP Lone pairs take up more space than bonding pairs which are constrained by two nuclei Electronic and Molecular Geometries are identical if and only if there are no LP on the central atom.

see Fig.1.10 text

see Fig.1.11 & 1.12
POLAR MOLECULES

see Fig.1.13
CO₂ is non polar while SO₂ has a dipole moment of 1.6 D. Explain the polarity difference.
MOLECULAR ORBITAL THEORY

CO₂ is non polar while SO₂ has a dipole moment of 1.6 D. Explain the polarity difference.

Answer:

Drawing the Lewis Dot structure is the key to answering this question.

SO₂ has a lone pair of electrons on the central sulfur atom. The SO₂ molecule is not linear, but rather bent like a water molecule. Like water, the dipoles do not cancel in SO₂.

Therefore, the SO₂ molecule is polar.

Lecture Notes for VSEPR & MO Theory

THE SHAPES OF SOME SIMPLE MOLECULES

POLAR MOLECULES

MOLECULAR ORBITAL THEORY

Answer: