AP Chemistry
Name __________________
Date ___________ Per ____
Chapter 8 and 9 Review
Please use your textbook to answer the following questions regarding covalent bonds,
VSEPR theory, and hybridization of atomic orbitals.
1. Draw Lewis structures for the following molecules or polyatomic ions:
a) POCl3
b) BrF3
c) NH4+
d) BCl3
e) XeO2F2
2. Draw all resonance structures for the carbonate ion. Describe the bond lengths between the
carbon atom and the oxygen atoms. Are they the same or different? Why?
3. Describe the molecular geometry of the following species and indicate the hybridization of
the central atoms on a-d only:
a) MnO4-
c) NO3-
e) SCl6
b) O3-
d) ClO3-
f) PCl5
4. Describe the geometry of a species which has:
a) three bonds and two unshared pairs
b) six bonds
c) three bonds and one unshared pair
d) five bonds
5. List all of the labeled bond angles in the following hydrocarbons:
H
H
H2N
C
C
C
C
C
C
O
O
H
C
CH2
CH2
C
H
H
H
CH
HC
N
H C H
C
CH2
C
OH
CH2
C
O
H
6. Consider the following molecules: SiH4, PH3, H2S. In each case, a central atom is
surrounded by four electron pairs (either lone electrons or shared electrons). In which of these
molecules would you expect the bond angle to be less than 109.5? Explain your reasoning.
7. Give the hybridization of each C, N, and O atom in 3-pyridine carboxylic acid.
Determine the number of sigma (σ) and pi (π) bonds in this molecule.
O
CH
C
HC
C
HC
CH
N
OH
8. What is the hybridization of carbon in the following?
a) CH3Cl
b) CO32-
c) CO2
d) HCOOH (on double bond to oxygen, one single)
9. Consider piperine, a molecule responsible for the spicy taste in some foods. Its structure
is:
H
O
H
CH2 CH2
C
C
C
CH CH CH CH CH2 C
C
O
C
H
O
C
C
N
CH2
CH2 CH2
H
H
a)
b)
c)
d)
Complete the Lewis structure for piperine.
How many carbons are sp, sp2, sp3 hybridized?
Which hybrid orbitals are used by nitrogen?
Give approximate values for bond angles marked a through f.
10. Calculate the changes in enthalpy (ΔH) using the bond energy data on page 351
in your text:
a) HCN(g) + 2 H2 (g)  CH3NH2 (g)
b) 5 N2O4 (l) + 4 N2H3CH3 (l)  12 H2O (g) + 9 N2 (g) + 4 CO2 (g)