SOLVE
Draw the Lewis structure.
Use the VSEPR model to identify the electron arrangements
around the central C and O atoms.
The C atom is bonded to three atoms and has no lone pairs;
therefore, it has a trigonal planar arrangement. The O atom in
the ßOH group has two single bonds and two lone pairs; thus,
it has a tetrahedral electron arrangement.
Identify the hybridization and bond angles.
C atom: trigonal planar, so 120 bond angle; sp2 hybridized.
O atom of the ßOH group: tetrahedral, so bond angles close
to 109.5; sp3 hybridized.
Form the bonds.
A -bond forms by the overlap of the p-orbital on the C atom
with the p-orbital on the terminal O atom.
EVALUATE As anticipated, the hybridization scheme of the C atom is sp2, leaving one
unhybridized p-orbital.
Self-Test 4.9A Describe the structure of the carbon suboxide molecule, C3O2, in
terms of hybrid orbitals, bond angles, and - and -bonds. The atoms lie in the order
OCCCO.
[Answer: Linear; bond angles all 180; each C atom is sp hybridized and
forms one -bond and one -bond to each adjacent C or O atom.]
Self-Test 4.9B Describe the structure of the propene molecule, CH3ßCH£CH2, in
terms of hybrid orbitals, bond angles, and - and -bonds.
Related Exercises 4.45, 4.46, 4.80, 4.95